I guess anything that has to do with Russia vs US (C&C), medieval/ancient times (Warcraft RTS games), or has a bit of craziness thrown in (think Red Alert, especially the superweapons)
I've heard that Civilization is fun, but I don't really know what that's like, aside from you can take over the world (I think). Being able to take over the world is always fun too.
Edit-Forgot to mention, they need to be somewhat modern (at least be able to run on Windows 7)
Edited by Albert Wesker, 20 September 2011 - 11:19 PM.