This has been asked so many times, it seems like I keep reading the same thread over and over again.
Member 1: Whats the best AGP video card for about $100-$200
Member 2: 6600 GT, it pwns
Member 3: Or you could get a 6800 GT if you have the money
Member 4: No, you'll be fine with a 6600 GT
Member 5: NO, the 6800 GT is so pwns the 6600 GT.
and so on....