Back when I worked at Gateway, we were an all-Intel company. In an effort to cut costs, we went with some AMD machines for a while, and those things failed left and right. It could have been the motherboards or other components, and I'm not convinced that the chip was to blame, but it left such a bad taste in my mouth (in addition to how rock-solid Intel is) that I've never purchased AMD.
That having been said, I'm not terribly picky. If it works and helps me to achieve purdy graphics, then I don't care.