Gtx260
From personal experience I have a GTX260 and it runs conciderably faster than the 8800GTX GTS's that I have had. Runs Nvidia Froggy fricken amazing fast.....
Truthfully the GTX260 will run any game perfectly.....Only reason I got the GTX260 over the 9800GTX2 was A.) the GTX260 is newer and B.) Heard some nightmares about heat issues with the GX2....Performance wise the 9800GTX2 might be a better performer in some games.