Robert Mitchum

According to the trivia, Robert Mitchum was the original choice to play the role that Gable took. I thought Gable was fine in the role, but honestly I think Robert Mitchum might have been better able to portray someone who'd be willing to compromise his values in exchange for remaining a free spirit. I know Gable has gotten a lot of acclaim for this performance but I think it was more "stagey", like a classically-trained actor playing a character, as opposed to the method used by the other principals.

I will say that the way the movie echoes the lives of the main actors involved - Monroe, Clift and Gable, with Gable bringing a sense of the "old guard" of Hollywood to the table, adds to the intrigue of the movie.