I just got registered here after a long while of searching for a good forum with decent replies. I stumbled upon your post and wanted to express how sorry I am about the luck grandgotti has had.
Here are 3 links that I use a lot. I am on the look of a 7950GT and facing the same dilemma 7950gt or 8600gts.
link 1: THE BEST site for GPU + features comparison (ATI+NVIDIA + ...): http://www.gpureview.com/show_cards....=445&card2=512
(select any card you like - i just put down the two of the current subject of discussion)
link 2: NVIDIA Chipsets comparison table: http://www.hardwaresecrets.com/article/132
link 3: ATI chipsets comparison table:
I think I have ended up with the 7950GT after deciding that I will never use VISTA. Thinking about Ubuntu 7.*
And to go with that a Collermaster IGreen 430W because although my Thermaltake W0023 (560W 22A on the single 12V rail) is enough it uses less power and more efficient which means less money on electricity bills.
Let me know if the sites helped you or if you have found any better ones for the same purposes. I recommend making those three sites in a sticky note for people with similar dilemmas to look at.