what Flipper said, except for Kinison,he was funny, but not in Rickles territory - in my opinion of course.
Someone above mentions he has as much energy as Robin WIlliams, energy yes, but you can't say the two of them are alike in any way, Rickles was a natural, Williams was just acting that way to so folks would pay more attention to him, it was his ego, same with Jim Carrey, both of them not funny, and nowhere near Rickles, a natural, funny comedic legend.