i had the same problem, ended up buying a GTX 260 and im really happy =)
i can play pretty much any game at the highest settings with 4X AA at minimum with really nice frame rates. either way, you can't go wrong, just try to find a brand that gives you like 5 years waranty at minimum or some games in the box, mine came with Grid, 3D mark Vantage, and some demos from Nvidias own software.