Intel. They are always simple and straight forward to set up and overclock if that is your thing.

I have a Prescott 3.0 D0 that will run 4.2 with the right RAM. As it sits with 2x1gb Corsair XMS RAM, it can only do 3.75ish but with very little voltage.

But when you get right down to it, either work just fine and you can only tell the difference in benchmarks and in multi threading back when Intel had HT tech and AMD only had single core.

Mike