I would say "none of the above". Nearly every board maker has some of it's boards farmed out. It really depends on the model number. Asus has some of it's boards made by ecs, which many have bad mouthed. But I've never had a serious problem with them. They just don't spend as much on support, which reduces their costs. If abit had been better managed, they might still be in business. Abit was my favorite for a long time.
You cant judge that none of the motherboards brands are not good without proof
I agree that it also depends on the model number but some company's make higher quality motherboards than others u cant just say none of the brands make quality boards.