Marlon Brando
Knowing he was a shoe-in to win best actor for his role as Vito Corleone in "The Godfather," Brando boycotted the Oscars in 1973. In his place, he had Native American activist Sacheen Littlefeather attend. She went onstage to accept his award, and when she read Brando’s speech about the mistreatment of Native Americans in film, she got booed