it depends what type of games or genre of games you are into before i can start making some recommendations...
...personally i play lots of various games eg:
CoH/CoV
Unreal
Halo 2/3
Fifa and Pro Evo
Battlefield
Oblivion
[recently played the godfather, was fun for a while with ok gfx]
You can always try and find a ps3 emulator with motostorm and test your gfx, but i dont know if you can and i wouldnt know how as i try to stay away from the illegal side.
I really dont think css is an option, cause I have to get half life 2 in order to play css. And I suck at it. I cant survive more than 2 minutes. lol. There are just too many pros.