ASUS has the best card ATM. But CS is a like shooting dice at a roulette table, and they have been caught a few times even in repair shop damaging the return device to deny RMA (lucky the entire process was documented over at HardForums, where even pictures was taken before card was mailed out.. It took the guy 4 weeks of PR hell to finally get them to honor the RMA, but they still blamed it on someone else for the additional damage done.
This is why i will not do any business with ASUS anymore, ever since i lost my connections there its only gotten worse.
eVGA (USA) has the best RMA experience period. AS long as it looks like you did not drag your video card behind your dog on a leash or use it for something it was not designed for, they have not yet denied a RMA claim for me..
They even allow the replacement of stock heat sinks to after market waterblocks, they just wont honor the warranty if they find your card has corroded because of a leak / water damage.
Gigabyte... LOLZ... no..... just don't...
PNY... again... LOLZ... dont....
MSI... always the more expensive card.... they have really really horrible budget cards, but the higher line, is really nice stuff.
As for RMA, i have not yet had to RMA a MSI, so i can not tell you for sure.
(not because they are reliable, but more because i have no used them enough in builds besides knowing not to buy the budget line.)