Well.... I usually go with the cheapest.
eVGA 5700 Ultra
PNY 5900 Ultra
Albatron 6800 GT (Surprisingly good brand)
BFG 7800 GTX 512mb
MSI GTX 260
I haven't had my 260 very long, so i can't really say, but i haven't had bad experiences with any of these companies, by far BFG and eVGA have been surprisingly good. Albatron provided a VERY VERY Solid card at the time, which easily overclocked to 6800 Ultra speeds, but i can't say i ever had any experience with their tech support or actual company