I was going to recommend Oblivion, but apparently you've played it.
I'd also recommend Bioshock, but there is no way that the 7600GS is going to be able to handle it. You might be able to do medium or low settings at 1024 x 768 or so.
Besides those games, there isn't much that's come out in the PC world lately. Supreme Commander is OK, but it's an RTS. Rainbow Six Vegas is a pretty decent action-oriented FPS. STALKER was OK. Besides that... there's not much going on. Call of Duty 4 is coming out in 2 months and is apparently highly awesome, and Crysis is due next year.. but Crysis will make your 7600GS weep like a little baby.
Try out the Bioshock demo.