SimCity4+Rush Hours - The classic. Thousands of mods. Possibility to play in HD resolution. Lots of fun with first cities. Later it gets boring. Especially if in the same region. Massive demand makes the game too easy. Bunch of unique landmarks/reward. Clear isometric view. Unfortunatelly lots of mod means unstability and lack of autosave option is sometime the reason of losing few hours of building.
CityLife 2008 - SimCity with 6 culture groups. 3D with some camera limitations. Quite fun to play, but money is the problem so you are 'forced' to play at fast forward to faster gather some.
Pharaoh&Cleopatra, Zeus&Poseidon, Emperor (China thing) - all based on Ceasar3. All fun to play, with huge campaigns. Great stuff.
Children of the Nile&ALexandria addon, full 3D - Less fun then P&C but seems more realistic. Although engine is 3d it is surprisingly uglier then Pharaoh. Again, quite a long campaign
Sim City Societies - this game is ripped to bits by SimCity fans but I bought it anyway, with Destinations expansions. It is fun to play (maybe little too harsh in scenarios and hardcore economy). There are some mods available but comparing to SC4 it's nothing. The game is really unstable on my rig and CTDs are often.
Space Colony - Fun game, but it would be funnier without all the sim crap. You must take care of the base on some planet and additionally the inhabitants (I think there are about 20 different characters) have different need and skills. You need to plan they work and spare time to keep them clean, happy, social and fed. Overall it's a nice idea and cool thing to check. 2 campaigns (peaceful and military) and some missions (For example one of the mission's goals: 12 clolonists. Try to make everyone fall in love with each other!).
Anno 1404 Venice - Venice addon apart of giving 'The Venice' also 'streamlines' the game. There are more side quest. ,more NPC-s, sabotage missions and tech tree and things like archievements and unlockable content (unlockable with the experience, not some 6.99$DLC). This is beautifull game, very gripping. A lot better then last Settlers incarnation.
CitiesXL - That game was suppose to knock down the SimCity4 and take it's place... but didn't. Nice 3d environment but with huge requirements. In my opinion the game gets quite choppy quite fast and it is annoying. There is lots of 'freedom' in building. The engine isn't based on square tiles so it looks more natural. But.. the buildings are just ugly and city looks really artificial. I must say I don't like it. I tried to like it but I can't.
Imperium Romanum/Grand ages Rome - I didn't play these games but reading the reviews and features they're looking like the Ceasar deluxe of some sort.
Startopia - Didn't play it but I remember that the demo was quite fun - managing of orbital space station, with different visitors, races and stuff.
Dungeons - Not Dungeon Keeper clone but rather something like RC Tycoon mixed with tower defense. At least thhat's what I've read about it.
Cities in Motion - New and cheap. You are not building the cities. You are organizing the mass transit in pre-made four cities. It might be fun.