Are you looking at an Nvidia Card or ATI? It would swing my answer.
For Nvidia, my favorite brand is XFX hands down. Although Evga is good and several others. MSI is nice, whoever has the better cooler and better support.
ATI, Sapphire is the largest seller. Some people don't like them, however I have never had an issue. Asus is nice, I have an asus, their support is good and quick. HIS probably makes the BEST coolers, but you will pay for it, which sometimes isn't a bad thing because if you plan to upgrade your cooler you may as well go with one of their IceQ coolers.