I like RTS games, but I'm looking for something a bit more tactical than the normal (Praetorians looks decent, and Medieval: Total War, too). I also like RPGs and shooters, though I'd have to smuggle a shooter into my house if I got it.
Games I've liked in the past are Age of Empires II, Age of Mythology, America's Army (though the servers are so overloaded these days that it's hard to play), Neverwinter Nights, Diablo II, Gothic (I'm eagerly awaiting Gothic II), Battle Realms, Deus Ex, and The Elder Scrolls III: Morrowind.
I've heard of Divine Divinity, and it got a good review from Computer Games, but it doesn't look appealing to me. I guess I've been spoiled by the amazing graphics and new concepts introduced by Morrowind and NWN. I'll check out the demo when I can download it, though.