I love Chris Rock's standup..he kills at it but literally 98% of his movies are TRASH. the only exceptions being CB4, Grown-Ups, and Top 5. Everybody Hates Chris was a good show though. Never really saw the one he had on HBO.
Pryor is the G.O.A.T, hands down.
Just about everything Eddie has done after Life has been trash but before then he was Kobe to Pryor's Jordan.
Chappelle is probably the least funny standup comedian of the four but the stuff he put together for his show was pure comedic ether. Ingenious.
I might have to go with Rock. He has greatest amount of stuff that I just can't watch out of the four.