Each manufacturer has examples of both reliable and unreliable mobo's. Whenever a manufacturer tries to compete in the budget segment they run the risk of producing a less reliable board. I believe ASRock has the most success doing budget boards that are reliable.
Top shelf motherboards are dominated by Asus. It's really their crown to lose. Ain't for lack of trying because Asus has made some really bad mobo's too.
I rarely consider the manufacturer in purchasing decision. It's much more important to me that the board has already proven to be reliable. I'm rarely an early adopter or on the cutting edge.