The XFX 6800GS is a great card for the MSRP of $249. Online the 6800GS is retailing for $209 online, making it an easy choice over the X800 GT and X1600XT at the moment. Performance on the X800 GT is good, sometimes surpassing the 6800GS, but it doesn't support Shader Model 3.0. The X1600XT has not reached stores yet, but early indications are the 6800GS is a better solution for most people.
NVIDIA has hit a home run with the 6800GS and the XFX version of the card is the best of them. With a stable overclock to 521MHz for the core/1.19GHz for the memory, the XFX 6800GS is an excellent buy for $249 MSRP. This is the GeForce6 version of the Ti200 and Ti4200 of yesteryear, already forcing ATI to lower their X1600XT MSRP $50 before the card is even released. If you buy two of these cards you have near the performance of a 7800GT. In most cases, it's better to have a 7800GT over two cards. On the other hand, not everyone can afford spending $350 on a 7800GT, and that's where SLI comes in.