Comedian Rodney Dangerfield, who built an extremely lucrative film and performing career on a single catchphrase (you know what it is,) has died of complications from heart surgery. Dangerfield’s act was exceedingly personal, and consisted mainly of one-liners at his own expense, delivered with a chuckle and a sad-sack shake of the head. He got his first big break on the Ed Sullivan Show, and acted in more than 20 movies. Dangerfield was 82.