Currently I'd go for the church of Gigabyte : good O/C products, cheap, tough, I like em.
Also, very bad experiences with MSI, XFX (their 5770 was total shit compared to the gigabyte one), point of view (RMA my *ss).
I don't like ASUS because it's always more expensive for no good reason.
eVGA seems to get mad reviews on their customer support, I guess that can always be good, but as I haven't RMA-d anything from Gigabyte I wouldn't know.