EVGA has the best RMA support as far as I am concerned. I like their tech support and RMA policies so much that I have around seven of their graphics cards ... from 6800GT's to a GTX 285 SSC ... and one of their 680i SLI motherboards.
Specifically, I had an EVGA 8800GTX 768M that failed about two years ago so I RMA'd it. I forgot to register the replacement card when I got it and I never thought about registering the new 8800GTX card until it failed about a month ago (artifacts).
Since EVGA tech support had never heard of the replacement card because I had never registered it, they were reluctant to authorize a second, freebie RMA; however, after speaking with one of the EVGA supervisors and asking him to check their records, we found the RMA shipping papers with my new card's model and serial numbers. At that point the supervisor made the appropriate adjustments to my records and I was not only able to RMA the replacement card, but was able to cross-ship the RMA to get the card as quickly as possible.
Mind you, I did remember to say "please", "may I", and "thank you" during my conversations with the EVGA staff.
I was so pleased with EVGA's personnel and policies that I put the RMA'd 8800GTX card into my X6800 rig and bought an EVGA GTX 285 SSC for my i7 965 rig.
And that's my story ...