I tend to rate Intel a tiny bit higher if gaming is the primary intended use of the PC, as their processors tend to push individual cores a bit harder (and most games still aren't designed to run on more then 2-4 cores at most despite 10-core processors being released), while AMD's are a bit better for running multiple processes across the cores... but the differences are fairly minor in the end. An Intel processor costing $500 is going to be pretty similar in overall performance to an AMD costing the same, though each will do certain things slightly better than the other.
not to mention that intel heats slightly less, which can come in handy when you push them to their limit.