I'm glad to see David Cross mentioned cuz I think he's probably one of the funniest people I've seen. For me it's delivery as much as timing.
Bill Hicks, hands down the best I've ever heard. I gave some tapes of his to a friend who was driving to Montana from Virginia along with some Sam
Kinnison and he listened to them almost non-stop.
Chris Rock has gotten very good since he got bolder and more honest/blunt.
Mitch Hedberg... I had never heard of him and saw him for the first time on that Comedy Central "Presents", I think. I had a hard time getting into
his delivery, but once I got the rhythm, he was killin me!