GTX 260.
Most places still have the 8800GT at the same price as it was at, and the 260 is twice as fast.
Also:
http://www.techspot.com/review/109-geforce-gtx-260-280-versus-radeon-4850-4870/page2.html
As you can see, GTX 260 = more ram, more speed, same price as the 4850.
Most places still have the 8800GT at the same price as it was at, and the 260 is twice as fast.
Also:
http://www.techspot.com/review/109-geforce-gtx-260-280-versus-radeon-4850-4870/page2.html
As you can see, GTX 260 = more ram, more speed, same price as the 4850.