That was quite an interesting post!  I also agree with your sentiments.  In fact, when it came for Shelob in Jackson's LotRs, the ultimate design they wound up using was the least scary one IMHO (you can see the range of ideas on the special edition DVD). 

But I believe that was intentional.

I think when it comes to movies and games, directors/devs don't want to make spiders as frightening and repulsive as they are in real life because you might well chase away your audience.  Arachnophobia is a common and powerful phobia, something that must be taken into account.  I have it and I confess that if a game had truly realistic spiders, I probably would not play the game that frequently as it would get on my nerves (or, more likely, I would mod them out ASAP).  

So, while I agree with your great post, I hope we get cartoony spiders and leave something more realistic for the modders. 

BTW:  did you ever hear of Camel Spiders?  Google it.  <shudder>

(Yes, yes...I know they are actually closer to being scorpions than spiders....but they freak me out nonetheless!  Imagine finding one of those in your house!  They're as big as house cats and twice as mean!  )

Nice tour of arachnid-land. I'd like to see the Giant Spiders replaced with a small family of Interesting Arachnids, Mostly Large. Guard tarantulas for the home, wandering wolf spiders to keep travelers wary, and maybe some industrious silk-makers you could hire to decorate and/or trap fortifications with cobwebs and orbs. Some recruitment-friendly giant trapdoor spiders would be swell, too.

Incidentally, trapdoor spiders might be one of the 'justifications' for the stubby leg thing.

Not necessarily true. While it is not necessarily true for all game, the ratio of a unit/monster/whatever total size to its bulk is quite important. If you have all spiders have long spindly legs, then you'll either be left with the "meat" of the spider quite small on the screen, or have the total size of bulk+legs be way to large.

In strategy game, it is especially important that the player can easily recognize a unit at a glance and spot it easily.

I'm sorry, I didn't mean to have you imagine an Orb Weaver sneeking through your window at night, crawling over your sleeping body before paralysing you with it's bite and have you watch in terror, helpless, as it slowly cocooned your motionless body. That's the last thing I wanted you to think of.

Well yeah I want differant species of arachnid with differant traits rather than a generic 'Giant spider' model. As for identifying on the tactical battle map I agree that they should be easy to spot, but on the Strategy map I'd prefer if enemies in general weren't so easily displayed (not easy with the pewter piece thing). For example, in the total war games many units are obscured with questionmarks unless you have a spy check the stack out which lends an air of uncertainty until you engage. I'd generally prefer to have the option to scout and investigate an enemy stack, or take the risk and attack the unknown. That's for another thread, though.

Well, if you want to get serious about scary insects, we need some members of the wasp family. Giant yellowjackets could make you wish you'd run into giant spiders instead.

And then there are all the fun options presented by their surreal range of parasitizing behaviours. I forget the name, but there's one wasp species whose adults can invade an ant nest, lay an egg in an ant grub, and after the egg consumes the ant grub to reach its own grub stage, it can use pheromones to trick the ant colony into feeding it like it was one of their own. Put that together with the right sort of life/death magic, and you could put some very interesting kinks an an enemy dynasty...

The Magic Spell "Stinging Swarm" is always a cool one. Especially as it spreads out from its initial target, to any adjacent target(s)s and so on, and so on...

Hehehe, I am majoring in entomology and I love insects!  Spiders to a lesser degree, but still awesome.  However, I find giant spiders to be VERY overdone in fantasy games.  I'm a little tired of spiders and would like something else, like giant praying mantids or ants or something.

However, if it is a must, I would support the OP's ideas.  Spiders would be much more scary if made with long skinny legs and very fast and agile, not slow and large with stubby legs.

I would TOTALLY love some giant praying mantis action.

Equally, there should be a faction that uses Dragonfly mounts