1.  I like being able to purchase anything that isn't a key strategic resource to the AI for the right price.  It's important that the AI be able to value things well (the GC2 AI undervalued low-population planets, overvalued high-population ones, and greatly overvalued influence points on large maps).  I also like having an AI that is consistent in its dealings - if it has an honorable personality, you can count on your favors leading to a lasting relationship - this is essential to get people to invest in long-term diplomacy, since unreliable AIs just aren't worth the effort.

Another thing the diplomacy system could really use is some way to coordinate efforts in a joint war - for instance, you could put a marker on a fleet requesting allied assistance, and if your allies like you enough, they could send nearby ships to move with it (the AIs could also request that you do the same, and give a relations boost for helping).

Another minor feature I'd like to see it for the AI to track "military effectiveness rating".  Basically, this number would be the ratio of the production cost of the ships you've destroyed over the cost of those you've lost.  It could act to scale your effective military power in terms of how the other AIs look at you, and could also affect the willingness of your allies to send ships whenever you request support.  This would help address the occasional immersion breaking effect of how you can be tearing apart your enemies' forces with your high-tech doom fleet, but they still think their military is "superior" on account of numbers.

2.  I haven't played a GC3 game through to completion, but my GC2 games could definitely last 3+ ingame years.

3.  For me, the most important part of a good 4X was articulated by Sid Meier in his definition of a game as a "series of interesting choices".  Whenever you look at how a feature interacts with the rest of the game, you should always be asking "what options does this feature present the player with?" and "do these options lead to interestingly different results".  An example of weak performance in this category would be an option between +5% damage and +5% defense - this choice would have a negligible effect on the game except in a few extremely specific scenarios, so it is not a interesting choice.  Another example of a non-interesting choice would be to be deciding on the next building for an industrial planet, and to be choosing between an 25% boost to industry, or a 25% boost to things like wealth, research, or other options that are obviously inferior because the planet does not specialize in them.  The correct choice is obvious, so the act of "choosing" amounts to just busywork. 

AI governors are an answer to some of the micromanagement problems that can amount to boring choices in the 4X genre, but I've always avoided them because they frequently make unwanted decisions.  But there is a solution to that - letting players make custom AI governors would provide the benefits of both worlds, while giving players a set of genuinely interesting choices when they set and alter the priorities of their various AI governors.

2. My most favorite Games (Round-based) are all Games of Sid-Meier's Civilization-Series. Civ CTP, Alpha Centauri, GalCiv II, Endless Space, Conquest of the new world. (Real-Time) Z, KKND, Empire Earth I, Warcraft-Series, Starcraft-Series. I also like very much all Tomb-Raider Adventure-Games.

1. Tohron really described it well, I share also his points. What I really didn't like is, when you try to help small Civilizations to regain their cities (when they are attacked by big and military-strong civilizations), sometimes it happens, that those Civilizations even go to war against you, even though you should be able to trade valuable resources with them with good conditions.

When you gain a technology of a other civilization, that is specific to those, you still shouldn't be able to build buildings that they can build.

3. A strategy game is good, when it doesn't have to much features (I don't mean the complexity but sometimes it is to overloaded, for example Civ 5 became to overloaded to me, because you have multiple World Wonders (to much for my taste), and all those other things like Religion, Spy etc.). Thats why I liked GalCiv II very much, because you could "only" bulid a small amount of different Buildings (Factories, Science Labs, etc) and each can be upgraded after researching new technologies. What I didn't like, is, that sometime it didn't pay off to research better technologies, because the upgrades become to cost-effective (to high production costs for better factories).

The productions should even be lower in my opinion, because with higher Tech you should be able to build buildings more efficiently.

I just wanted to say also, that I didn't buy the beta of GalCiv III, so I don't really know, what the differences really are to GalCiv II, but I saw some videos on youtube and it looks good!

1. What specific features of diplomacy do you traditionally like the most? I want you to be as specific as you can be. Which parts of diplomacy from any game do you like the most? What parts do you remember long after playing the most?

None of it. It's just a annoyance.  They are either friendly or they are not.

2. Looking back, how many turns do your favorite games last? This is important to know the specific number of turns the game in Question lasted. 

As far as I can before the game starts to have problems (well into the hundreds)

3. Consider all The 4X strategy games that you have ever played. How do you define what is a good strategy game or a bad one? To you what makes one strategy game good fand another one bad? Consider different memories you have of those games can you remember the parts that made you enjoy that game the most?

GOOD - Interesting and well thought out tactical as well as strategic game play in equal forms (not mainly one or the other), with a progression that's give you some sense of power.  A personal touch to your main character and heroes, so That you give more than a toss about them.

BAD - Mostly,4x games have become somewhat sterile, they have lost their personality and soul, and become just numbers.

Having thought a bit more about my answer to #1

A really good mechanic of the Civ 5 diplomacy once they fixed it was how the combined action of friendship declarations (which made the friends of each civ involved like each other) and denouncements (which made the friends of the civ doing the denouncing dislike the civ being denounced) tended to split the world into blocs.  It made for large scale wars and alliances and felt pretty organic.

I'll give this a go.

1) I like the diplomacy in GC2 trading techs,swapping economic and research treaties and alliances and I lked it in Sword of the Stars 2. The worst game for diplomacy was The Lost Empire - Eww! (too restrictive)

2) The longest game I've finished in GC2 was 32yrs 6mths so 1500 turns+ But I had saved games that were just as long till my wifes comp died and wiped 4 years (real time) games play out.

3) Hmmm! I like Sins of a solar empire,Homeworld 2,SW:EaW and FoC,GC1+2Ultimate Ed (mainly play ToA), Stronghold Deluxe+Crusader and Stonghold 2 (but I prefer Crusader),Tropico Gold,Sim city 4,Civ 4,Beachlife. Anyway I find the following aspects of a game if done right make it highly playable:

Camera views/free cam/zooms like sins camera and GC's combat viewer.

User Interface/ease of use if the basics are easy do you can build up to the more complex tasks (which is why I still play GC2 and will till I can get hold of GC 3)

If a game says "Design your own ships" on the cover then when I actually get to play it its pre-designed hulls that I can only put equipment on I get pee'd off (Gal Civ 2 has spoiled me as I love building ships from scratch)

Good tutorials eg Stronghold series and GC2

The music - Often overlooked but Background,Event,Combat - Get this wrong and it can grate on your nerves Best=GC:DL vocal theme song,  Worst=The Lost Empire electronic synth crap I had to turn the sound completely off.

Combat must be enjoyable I like both tactical combat (Sins,SW:EAW) and GC's combat Viewer.What I would say that GC falls down on is the land/planetary invasion screen if we could have a combat viewer version for planetary battles that'll be great!

I like the freighters/mini-freighters in GC2 for trade routes rather just straight trade lines between planets (didnt like this in Sots) also the fact that I can arm them if necessary?

Free travelling ships rather than travel lanes (eg can go everywhere on map) I didnt like this in Sins and SW:EAW and Sword of the Stars but I can live with it.

plenty of different factions to play or create your own custom races/faction? is a must to stop boredom of playing the same race/faction over and over again-variety is the spice of life and games.

Sorry for the WoT, Have a on me!

1. What specific features of diplomacy do you traditionally like the most?

Even though it's a given, having some way to quickly balance the two sides of the deal.  So for example, in GC2, the bc needed to make things equal would be picked out.  In Civ, asking 'What will it take to make this deal work?'

I like long-term co-operation with other civs, as opposed to just taking everything by force.  And if the terms of co-operation change through the ages, that's something I can live with.

I think that more than anything, I remember those times when Civs stayed in character and didn't try to stab me in the back.

2. Looking back, how many turns do your favorite games last?

Hundreds.  Close to a thousand for GC2, and in Civ 4 for example I would typically play Marathon from the Ancient age.  With slower tech progression.  And timed victory turned off.

3. Consider all The 4X strategy games that you have ever played. How do you define what is a good strategy game or a bad one?

I guess I would say that the thing which makes a 4X bad is not having the right level of challenge.  The AI opponents or the environment should not be easily beaten or tamed.  I remember thinking that in Alpha Centauri or Civ II, for example, you had a lot of tools to radically alter the environment, which basically meant that at one point or another you would win simply because you were godlike even though you hadn't actually passed any of the victory conditions yet.

Having a challenge doesn't necessarily make a 4X good though, it just means that the player will keep coming back for more.

What makes a 4X good? Um, well I think with a lot of games allowing you to customise (for example GalCiv or Civ, being able to customise your Civ)  I think it's about the player feeling like the timeline of their struggle tells a story of victory (or defeat) and that their choices and actions helped to shape that story.

It's that lucky and memorable discovery of a high-PQ planet or Precursor Library in GalCiv which helped things along.  It's that goodie hut which yielded a much-needed technology or Settler.  It's deciding not to trust a particular AI player and being justified when they try to take over the world - and you're ready for them even if the other players aren't.

You are a storyteller, and a general, and a diplomat, and sometimes a brutal despot who had slaves whipped mercilessly to get results.  You've been there at every step along the way, from that lowly first Archer unit right up until the thermonuclear holocaust which destroyed most of the world.  Oops.  There's continuity, you know, your aptly-named capital city standing the test of time.  Unless someone razes it to the ground, of course, in which case it continues to be ashes until you get a settler in there to rebuild it.

What is good about a 4X is expanding your mind to consider new possibilities, new strategies and different ways of playing.  So for example, in Civ 5 I liked that each civ has different advantages and ways of playing.  In GalCiv 2, the default races gained unique improvements techs, and abilities.

It's not about cranking out generic victory X in the least turns possible, or achieving a million point score.  Well, it may be to some, but not to me.

It's about exploiting your knowledge of relations between the other civs to make yourself appear to be the trustworthy trading partner.

It's about sneaking your spies in to sabotage production (without going complete overkill like in Civ 4 and having so many spies that your opponents can't produce anything).  Or there's intrigue, which was introduced in Civ 5: Brave New World, and allows you to warn players of impending sneak attacks.

I think in a nutshell, 4X games are good because there isn't one cookie-cutter way to win, things happen and you may have to adjust your plans on the fly.

Hope this helps!

1. Trade agreements (allow trade routes), trade/gift/request specific resources (any resource), military access/open borders, defensive pact, non-aggression, research agreement, form/dissolve alliance, negotiate peace (via any resource available), declare war, request faction go to war/peace with, insult/compliment.  I would love to see the ability to goad two factions into declaring war on each other.

2.  Hard to say.  I've enjoyed short games that take a day, and long games that take 3 months.  Both of these are usually set by the map size and/or speed of the game.  I've never really paid attention to the number of turns, especially since you can really slow some games down (like Civ), just the overall amount of time.

3. Having an interesting, and active, early game in which to lay your foundation is important, as is the ability to shift that focus fairly early on if/when your situation changes.  Having the ability to adapt as different events unfold.  Having a variety of victory conditions is also very welcome, as it encourages different play styles.  My most memorable victories have usually been those that were non-militaristic, one of which I built zero military units.

Two things that always annoys me is when the AI is not consistent, and when they bombard you every other turn (eg: Civ Open Borders).  There should be specific positive and negative reactions to everything you do, and those should add up to determine how the faction reacts to you. Most games already do this. but one of the very few things I liked about Rome 2: Total War (even after a year of patching) was that you could see the breakdown of everything the factions liked/disliked about you, and you could watch as those actions degraded over time.

1.  I like the AI (or other players) to be able to negotiate for almost anything, I would love it to notice if a player is just attempting to rip them off constantly, or if one is showing mutual benefits.  I would like to have an AI that could help you out in a war and actually notice there assistance (Such as x player is wiping me out please come to my aid, then you see y player hitting x player hard).  Having an AI notice if you do the last point for them, if you come to their aid have them reward you if they can or if they are calling it quits have them join you.

2.  I love long drawn out games, games that last for weeks or months without getting old.  Something that can adapt and be as interesting to play at turn 10 as it is at turn 1000.  Galactic Civilizations II is this game for the most part, there is some repetitive things that get old at the late turns of the game, however, this is very close to it.   With that being said I also enjoy short basic 4x games that are evenly matched such as moon base commander, not very complex but can fill a half hour of time.  Both examples can be good when need time to fill, I love the long games when I time to sit down and play for hours and then come back to it and continue.  I love the short basic game that can be non-repetitive only last for 30 minutes or so but doesn't get old after you play 50 games, maybe unlocks certain features after x games won or so on.

3.  I kind of pulled #2 into this but, to me the best games out there are games that keep bringing new things into the game, giving you goals to reach for even after a game has lasted for 2000 turns.  The largest killer for any game is a game that you get into and after an hour or two you have reached end game as far as new adventures or new items and the rest of the game, however long it lasts, is just the same thing over and over again.  This is why I love long tech trees in Galactic Civilizations II (wish it was longer or slower to research) or other rewards or special events that exist in other games (none specific).  The largest flaw in games these days is that after a few hours in the game there is nothing new or game play is too small (EA's flop SimCity [2013]).  In my opinion Stardock is thinking large, what can we do and listening to it's players, look at the anticipated mega maps for Galactic Civilizations III and 100 players.  I know a lot of players are very intrigued by this and hope all the bugs get worked out for this to become a reality (which I think you will find a way)  Personally I say why stop there, lets go larger and more players but, I have to be realistic. 

Game types I'd buy jumps outside of the scope of the question and generally adds just games that I'd be interested in...

3a.  4x games that meet the specifications above...

3b.  A tycoon type game similar to Railroad tycoon 2, or Locomotion.  Personally some games in this day have gone away from the basics, keep it simple yet keep the depth, too often (Railroad tycoon 3 or Railroads) try to improve these good games and loose the depth.  Example for those that have played either of these games I would love a tile type game that is huge compared to these games that expand on the depth and game play.  Looking at Railroad Tycoon 2 adding more to the AI, bridges, more depth to the building or city growth or even founding on the map.  Looking at Locomotion and giving you slower city growth and expansion, making it easier to drive the other players bankrupt (as in this game it's nearly impossible)

3c.  A building(tower)/city/planet simulation game (SimTower, SimCity, SimEarth)  EA/Maxis hasn't ever gone back to the basic games that drew the players interest to them with the exception of SimCity.  These three games were great customer builders for Maxis before the merger and EA has lost their focus and depth.  I feel that if a game company out there would revisit these great games they would sell especially if they drew synergy on the other games.  here are some thoughts...  A SimTower type game in a 3D type structure, allow you to build up a tower, very similar to SimTower but allow for one to customize almost anything in the game, such as your condos, offices, hotel rooms, diner's, or any other type of room you could put in the game.  A SimCity type game that takes the great aspects of SimCity4 and expand on it with other ideas such as SimCity2000 network edition, as well as some of the better aspects of the newest SimCity and allowing one to also place the Tower somewhere in your city.  Finally a SimEarth type game where you can build up your planet from a lifeless rock to a thriving planet, again expand on the basic game allow it to grow to a point where you can place your cities into the planet and this gives reward... 

3d.  A tycoon type game similar to Monopoly Tycoon, a more simple game that keeps interest, a game that one can buy properties and build up an empire, looking for more complexity with products and services offered.

All of this being said I'm sure one would have to be very careful not to infringe on copyrights but, these are the games I'm looking for.  I'm very interested in the Trading Company game in which Stardock is associated with in part, however, can't put the budget into it now, and it may need to wait for the release.  Can't wait to see what other adventures Stardock is going to announce in the future.  All the games mentioned above I do have a lot more detail on my thoughts on how these could be great I just painted a basic picture above.  All games I look for are tile based (hex or square) versus free form.

I'm going to mostly answer the question about Diplomacy, because it is something that often gets neglected.

First up I like it when there are multiple states of peace and war.

A lot of games it is either complete peace/alliance or outright war.
I prefer a more scaled approach:

- War: little need for explanation. This is actively seeking your destruction

- 'cold' war: This state automatically starts if a 'neutral' factions territory is trespassed or if their units are attacked in non-owned areas. They won't actively war against you, but they will build up defenses in their owned territory. Some more aggressive factions may skip this and go straight to war.

- neutral: both parties are neither at war nor really at peace. They will avoid each others territory but will attack the others ships if encountered in their own, or disputed territory. AI doesn't go out of it's way to attack and tries to avoid contact where possible.

- Non-Aggression pact/ Peace treaty: a step up from neutral, this is the agreement that each party will stay away from the others territory and won't attack the other parties units/fleets/soldiers. If you enter their territory they will attack and counts as you breaking the deal.

- Defensive Alliance: Both parties will aid each other by going to war against anyone who declares war on either party. If you are the one to declare war, a defensive ally is not obliged to join you.

- Military Alliance: This is the usual alliance, You will join in any wars that the other party is involved in and vice versa.


Then of course you add other treaties like Trade agreements, Open borders, share Intel etc.

Another thing I thought was really cool in Space Empires 4, was you could use diplomacy to create 'Federations' which acted like an alliance bloc like NATO.
Member races could attempt to pass 'bills' with things like sharing tech, restricting the use of certain weapons (like biological etc) and so on. It was a pretty cool feature in my opinion.

1. I never liked diplomacy much and that because AI has never been smart enough so far. In CIV 5 like others mentioned AI was a crazy psycho it didn't matter if you were friendly or wary AI had been denouncing me all the time even if we had good relations and he was far away on the map. I'd like either a really smart AI who doesn't act agressively all the time or something very basic for tech trading or other and no spies!

2. 200-300 turns or more and that's because I always play the biggest map I can get even by using mods to get even bigger. Civ strategy games have 2 phases 1st expansion and 2nd domination (with war or any other way).
I want my game to last my empire to grow and I mean really grow controlling many star systems and be really advanced see them becoming something, something I created before I get into a war with some other race.

3. Simply and always MOO2 because it was a game that was taking you really in.. the music was amazing, the starbases, the terraformations, the battles.
I have played countless strategy games good ones and bad ones a good strategy game for me is a good combinations of mechanics and graphics.
When I play a strategy game I don't want to play fast and win, I wanna create something big it will take long time to finnish, ANNO 1503 is a good example it was a great game with nice graphics you had to build and expand your cities something that was taking really long epic long.. but it was rewarding it was live and working machine. Freelancer another game not a strategy one but one of my favs too and that because of the vast universe and freedom of choice to do anything you want and of course a really beautifull space world. Sometimes I wish there was a strategy game that could combine the mechanics of strategy with amazing 3D graphics like in Freelancer or any similar.

Great mechanics that change from detailed to simpler as my empire grows e.g. I control 1 or few planets and I have to control them manually, researching a tech later gives me the option to create a set of rules and things and just choosing what I want for each planet rather building all the same again and again. GC3 perhaps?
Great graphics a big, immersive, vast universe with countless star systems and variety of planets. Incidents big or small unknown possibilities, strange things that can alter the game or not but would definetely enrich the game unlike a set of "random" things.

A game that you create something and you enjoy seeing it becoming really something rather trying to win the game and finnish it.

1. I like diplomacy when it allows for effective short term negotiations, such as tech trading, as well as enduring and mutually beneficial relationships with other factions. However, this requires that there be more options for long term alliances than just a mutual defense pact and open borders: trade and research agreements, for example. It also requires that your allies not break any agreement within a few turns of making it, despite nothing being done to antagonize them. If these conditions are not met then long-term diplomacy simply isn't worth the time and effort.

2. I'm not sure how many turns my favorite games last, because I almost always quit before they are over. I love playing long-term games on massive maps, but I inevitably hit a point where managing my huge empire becomes too sluggish and inefficient to be fun. By this point I often have a massive advantage over the other factions anyway, so much so that I've essentially already won. Playing out the game and getting the formal victory screen just isn't worth the frustration and boredom. Dealing with this problem would require a method to efficiently manage my empire no matter how large it is (the new "Commands" system seems promising) and AI that can provide a viable threat throughout the entire game.

3. For me, whether or not a 4X game is good or bad is a matter of complexity, efficiency, and personality. Complexity is basically the amount of unique and interesting stuff in the game: factions, techs, armies, spaceships, planets, etc. Without this, the game feels simplistic and boring. Efficiency is how well the complexity is managed: how effectively you can manage your empire and respond to the events of the rest of the game universe. Without efficient UI, the game feels more bureaucratic than fun. Personality is how well the game conveys the atmosphere and style of the its universe, usually done through clever writing and unique design. Without personality, the game feels dry and unremarkable. Having complexity, efficiency, and personality makes for a great game; lacking one or more elements results in a weaker product. Stardock games usually excel in complexity and personality, but, like most 4X games, they struggle with efficiency.

1)  I really like the war score system of Europa Universalis 4....if you are unfamiliar with it, I highly suggest checking it out...basically, a variety of factors (holding the "war goal", winning/losing battles, blockading ports, occupying provinces, etc.) contribute to the warscore (which ranges from -100% to +100%), which in turn affects what you can bargain for at the peace table...

It makes wars a lot more meaningful in many ways...for starters, the reason you went to war determines the war goal, which allows for the possibility that all wars are not the same (a trade war just won't play out the same way as a conquest war)...along this line, what each item costs at the peace table depends on the cause for war -- if you went to war over trade, it's going to be harder to ask for territory vs. asking for trade power...the system also makes it harder to pick on smaller nations who have big allies, since you have to work your peace through the big ally (and that will require you make headway against them, not just the minor you attacked)...without playing the game, it's hard to appreciate all the qualities of this system but overall I have found it highly enjoyable...

The only thing missing is the ability for both sides to give concessions simultaneously, which I find highly important...

2) The strategy games I have loved the most (Civilization, Total War, Alpha Centauri) tend to have around 200-400 turns...however, a turn in Civ V is a lot shorter than a turn in a Total War game (which may have real time battles during it)....I usually finish my Civ V games (which usually require that you go all the way into the modern era), but not always my Total War games....

3)  Some things that make strategy games good:

• Depth -- Alpha Centauri was the real master here, the quotes and philosophy and ideology in the game gave a sense of depth that was phenomenal -- you felt attached to the faction leaders, and every single item in the game felt in some way part of a specific ideological order
• Strong late-game -- Many games become boring once you know that you are going to win...Civ V I think did a really good job at making the mid and late games more interesting through its expansion packs...specifically, 3 of the 4 victory options in Civ V became viable around the same time, and it was really hard to be in a position to win through all of the different ways...if you were going for a space race victory, you weren't really competing against other nations in terms of tech -- you were having to make sure you tech faster than the culture civ was getting influence so that you went to Alpha Centauri before their culture dominated everyone else...it kept you on your toes through out the whole game and made it fun until the very end...
• Balance & Diversity -- It's really important to me that all factions are equally viable...sure, some may be better at some things or slightly stronger/weaker on certain maps, but on average they should all be equally capable of winning...on the same note, each faction should play different, should feel different, and should not in any way resemble a carbon copy of another faction but with different graphics...this is the primary difference between GC2 before and GC2 after Twilight of the Arnor...before, all the factions basically played the same, but once ToA came out, most of them felt radically different and that was an important element...