Ive just gone to windows 7 and the game looks the bollocks now. Yer, it doesnt look like bad company 2 or anything since its like a 6 year old game, but its still one of the most popular ones.
I can play crysis on my 3 year old system with most settings maxed no problem,1gb gainward GS 8800gt, 2gb of ram, q6600 overclocked etc. The multiplayer for that is pure shit though, as is the crysis warhead multiplayer game. COD is ok if you like fast paced nade/ claymore spamming. Left for dead 2 is pretty good.
Most of the games your going to have to buy though.