For gaming at 1080p it really depends on how much you want to spend. For $180-200 the GTX 460 or HD6850 are very good deals for the money. They are actually quite good for 1080p, especially if you give them an overclock because they can both OC a large amount(30%+). If you are willing to go over $300 then wait for the new AMD cards which should be out in a few days(supposedly.)
You should be looking at the GTX 570, not the 480, but wait for the HD59xx cards. Even if you don't get one it's likely the prices on the Nvidia cards will go down a bit once there's direct competition.