Goatbrush: I'm sure it's been answered already but 64 pages fffffff. What are the company of heroes games like? and how demanding of hardware is Darksiders?
Company of Heroes is an RTS. Let me see how to explain it... Get Starcraft, make it slower, and put a hell of a lot of detail in how you control your units (as in, soldiers take cover on objects, can enter buildings, tanks have less armor on the rear...), and that's it, more or less.
Yeah, it has little to do with Starcraft, I just used that as a starting point because I don't know what you may have played. I could also say Ground Control with unit production and cover for infantry, in that instead of mass producing units and sending them semi-blindly into battle, you spend more time guiding them along.
Anyway, it's better to see for yourself. It is pretty good.
As for Darksiders, it shouldn't be too heavy. Problem is, there are almost no video options other than resolution IIRC, so you will either run it well, or not at all.