Will Smith: Neo, The Matrix
Will Smith opted out of Keanu’s role because, as he said in an interview with Wired, the film was "a difficult concept to pitch. In the pitch, I just didn't see it."
Despite feeling differently about the film in retrospect, the Fresh Prince has no regrets. "I would have messed it up," he admitted. "At that point I wasn't smart enough as an actor to let the movie be. Whereas Keanu was smart enough to just let it be. Let the movie and the director tell the story, and don't try and perform every moment."