I have actually had good luck with video cards in general. last 2 failures I had have been.
GTX 670(this sucks because it failed[crashing in games and folding@home] within a few months)
Geforce 4 4200ti agp <- yeah that was the last one before the 670.
So my x850 pro flashed to xt, x1900xt, 4870, 5770, 5870(this card is a work horse, used it for years) all still work. all of those cards are reference designs.
On the Nvidia side I still have many old Geforce 2's the replacement 4 ti 4200(fan failed, but the card was fine.) a 4mx 400, 8800GTX 650 ti and the current 670.
You may see a jump with less Nvidia cards(8800gtx -> 650 ti), but Vista drivers from Nvidia DID leave a bad taste in my mouth(600 dollar card with NO support and just one crashy driver for over 9 months). I would have blamed Vista if I did not have other cards to test with, but it was actually a driver thing, my X1900XT(and its lower performance compared to the 8800gtx) had to be used since I did not have money to grab another card and the 2900's from amd had been power hogs for sure.
So yeah, overall only 2 actual card failures in all this time.
OK, I gess is a matter of having good luck then, whatever ATI or Nvidia