Marlon Brando's performance in The Godfatheris one reason why the gangster movie is heralded as a classic, and his unmistakable voice was based on a real-life mob boss. The cast of The Godfatheris one of the best ever assembled, with Al Pacino, James Caan, Robert Duvall, Diane Keaton and more all at the peak of their powers. Still, it's Brando who often steals the show, and he's the one who was awarded the Oscar for Best Actor, despite his limited screen time in The Godfather.