We just arrived at the most used enthusiast monitor resolution, 1920x1200. Personally I play all my games in this resolution. Throughout the board good numbers, but again it is the GTX 460 series that catches my eyes. But yeah even a R4770 with 512Mb will still hold up well. Also good value for money here is the R5770. You can pick these up at 150 USD these days with 1024MB graphics memory.
Once we enable 4xAA we see an extensive shift in performance this time around. The GTX 260 really is your starting point, and if you aim for an average 60 FPS it is once more the GTX 460 that would make the most sense money versus performance versus features wise.