I would get the ATi 4870, or the 4870x2 when it comes out. The 4870x2 would be basically like doing a Crossfire setup in one slot, which is good because your mobo doesn't support crossfire. The 4870 is still a very good card, but if you have money to burn, go for the 4870x2. Or at least wait for it to come out so the 4870 will be cheaper. And if you must go NVidia I would get the GTX 260. The GTX 280 is better but not for the price, plus you could SLI another one later.