I've always found Russell Brand to be a hilarious story teller on talk shows. For some reason, that never translated to his stand-up act, which comes-off as Andrew Dice Clay redux. His strength is improvisation, not delivering a set.
Check out his new show on FX, "Brand X". Obviously Russell Brand is a love-him-or-hate-him type guy, but I find that show hilarious, smart & spontaneous. He has an academic straight man on there as a check against his own highschool-dropout observations.