HBO, Dec. 2, 8 p.m. ET
Spitting out put-downs, comedian Don Rickles looks like a bilious frog. Offstage, though, he seems to be a better-adjusted human being than, say, the late Rodney Dangerfield. This documentary, which includes interviews with cutting-edge clowns like Chris Rock and Sarah Silverman, is the last thing you’d expect: warm. Just a little.