I went for the eVGA 7900 GS KO. Awesome cards. I really can't be happier with them. Right now they're going for about $200. Great performance for that price. I would say that they're really the sweet card for price to performance ratio right now.
GeForce 7900 GS review at nvnews.netOne thing to keep in mind is that they are only DirectX 9 cards. So if you're really wanting to play games like Halo 2, Crysis, or Alan Wake in all their glory, you'll need a DirectX 10 card like the 8800.
Whichever way you go, I would definitely recommended eVGA. They've got a lifetime warranty which includes coverage for overclocking and aftermarket mods. Basically as long as you don't physically break the card, they'll replace it. As well, they have the Step-Up program which allows you to trade in your card within 90 days and you pay the difference between your current card and the new one. The only downside is that for Canadians, we do have to pay for shipping and possibly duty if Customs can't read that it's a replacement part.