I always go for EvGA. They have a life time warrenty. Obviously the 7950 is the newest card out there but with 10x coming out soon, no real point in spending the cash.
If I were you. I would go with XFX 7900 GS 256mb Extreme Edition.
I built two computers. One with the GT version (more expensive) one with the GS version (cheaper). I saw 0 performance difference between the two. The only time I saw a difference, and a slight one at that, was benchmarking. However for games, my frames were the same and the picture quality was just as good for both cards.
So i sold the system i made with the GT and kept the GS. Thats my expirence at least.