He Wants to Be a ‘Likable Prick’ — Robert Downey Jr. as Iron Man

Stan Lee originally based Tony Stark on millionaire recluse Howard Hughes, whom he called "one of the most colorful men of our time: an inventor, an adventurer, a multimillionaire, a ladies man and finally a nutcase."

Robert Downey Jr. took that description one step further when portraying Stark and said the role was challenging because he had to make a "wealthy, establishmentarian, weapons-manufacturing, hard-drinking, womanizing prick into a character who is likable and a hero."