9. Iron Man/ Paul Newman
Although it's hard to imagine someone besides Robert Downey Jr. ever portraying Marvel's eccentric billionaire, Paul Newman would probably be more than up to the task. Combining popular appeal and talent at a level rarely reached, Paul Newman turned in some of the most iconic roles of his generation including Cool Hand Luke and Butch Cassidy and the Sundance Kid. He was known for his coolly detached sense of rebellion, often playing anti-heroes and rebels. His sense of humor, cocksure attitude, and inimitable swagger make him an ideal choice for Tony Stark, who Downey Jr. has made synonymous with wit and devil-may-care attitude. Newman would be simply brilliant as the "genius, billionaire, playboy, philanthropist", possibly equaling Robert Downey Jr's own interpretation. It wouldn't be exactly the same, but in his own way, Newman would probably become just as popular and endearing.