Mac Lethal is my favorite rapper of all time. Long before Youtube he was killing it in the battle rap circuit and is highly respected in underground hip hop. Very much a Louic CK-type of mind. He raps about a lot more than pancakes, and isn't a "comedy" artist. I'd call his angle more intellectual/observational for the most part. And to the guy who called Mac a racist, he is on a black dude's record label and given his lyrical content there is nothing racist about the dude... Plus I know he's a an R&F listener. And yeah I agree this shit it cheesy, but I thought people deserve to know what the guy's about.
Twista is (was?) faster than that (e.g. his first single "Emotions"), and there's another guy altogether who holds the Guinness record, but I don't know how popular he was outside of that.