I just stated who was "The Guinness Book of World Records" fastest guitarist before they discontinued that segment of it.
Marcus Paus. Go back to about the 12th page of these thread and look for the user lalimeacefolle and he posted a link to one of his songs. Michael Angelo can't touch that, even with 4 necks. I'm not saying he isn't fast, because he is, but not as fast as Paus.
But they're both pretty boring. I prefer more melodic stuff like Vai and Satch.
Sometimes I hit notes only dogs can hear.