You're wrong on this one
A GTX460 (I haven't heard of GTS460) can max COD4:MW, AC:B and Portal 2 at 1080p even with 4xAA, provided your CPU does not bottleneck the card. I'm still using a GTX460 and most games still run fine at 1080p. I don't know about Killing Floor as I don't have the game. The GTX460 can also max everything except AA at 1080p in AC3 provided you have a good CPU (i5-3470/3570K) because the game is quite CPU bound as well.