I'm not much of a gamer anymore, hence my MB purchase, but I'd like to pick a cheap game up just for killing time. Any suggestions? I know I could just pour over countless reviews, but I trust the opinions of people here, especially when it comes to what games will run best on my lackluster GMA video. I'd prefer something along the lines of an RTS, RPG, or something similar that won't really require an external mouse. It can be for either OSX or WinXP.