Gene Hackman, 'Young Frankenstein'
Keith Richards, 'Pirates of the Caribbean: At World's End'
Mike Tyson, 'The Hangover'
Christopher Walken in Pulp Fiction
Chuck Norris from Dodgeball: A True Underdog Story
A few of my favorites, not all ready mentioned.
Kurt Vonnegut in Back to School – When the wealthy Thornton Melon goes to college, he hires noted author Kurt Vonnegut to write a paper about…Kurt Vonnegut. Unfortunately, the paper gets a failing grade, and, according to the professor, “Whoever did write it doesn’t know the first thing about Kurt Vonnegut.” This leads to Melon giving the writer an earful over the phone and threatening to call Robert Ludlum the next time he needs a paper written.