Richard Pryor

Groundbreaking and controversial comedian and actor George Carlin began performing stand-up in the 1960s, including appearances on "The Ed Sullivan Show." He was part of a generation of renegade comedians, including Lenny Bruce and Richard Pryor, who challenged censorship and ... moreobscenity regulations with their frequently off-color material. Pictured here performing in 1971, Carlin died June 22, 2008. He was 71.

(Andrew Kent / Retna Ltd.)