It really depends on the game, even at that resolution. If you can and it's not too much more expensive, then a 5750 or 5770 would be the way to go, and you'll pretty much assure yourself you'll as good of a performance as you can expect in any game. The 5670 would still be a good option. I don't particularly see a bad choice between them. I would lean towards the 5770, as surely you're about ready to upgrade that monitor, or maybe you'll connect it to an HDTV someday, and you'll want a little extra horsepower.