Monty Python, hands down for me, as they found a way to transcend absurdity and somehow blend it together with varying degrees of satire, black comedy, highbrow and lowbrow, the likes of which I have not seen again.

Chappelle's Show is highly entertaining, especially when they explore race relations.

Old, Old episodes of SNL are also great, but right around 1986, they really lose steam.

Classic sketchs from The Tonight Show with Johnny Carson as well as the endless pranks from "You Bet Your Life" with Groucho Marx also come to mind.

Take care all.