ah well, then you want to get a 7770. the one I listed is generally considered one of the best, and it'll leave you enough to buy ARMA II (if you haven't already)
although to be honest, I'd wait for the standalone. the mod is buggy as hell, and if you don't have ARMA II, I don't know anyone who plays ARMA unmodded.
yeah. well, if you already have ARMA II, then the mod is definitely great! I'm just not about to suggest that you buy ARMA II when dayz will release standalone later.
anyways, the 7770 will allow you to play graphically intensive games like BF3 and crysis 3
at decent settings and good framerates.