katt williams is a good comic. His energy is what makes him good. His jokes are ok but the way he commits to each joke pushes it over the top.
Russell Peters got lucky once and made a good special, everything after that is making fun of indians and other ethnic groups because he can and its a cheap laugh. He is the indian equivalent to many black comics who basically do 'white people do this, black people do that' routines.
Bill Burr is one of the best comedians working today. His 1 1/2 hour uncut special on comedy central is the funniest stand up i ahve seen, behind any of chappelle's specials. If you guys haven't seen that you are missing out big time.