Joseph L. Mankiewicz is not remembered by most today as one of the finest directors in Hollywood history, but this film proves that he is. Already a success by doing sophisticated American dramas such as A Letter to Three Wives and All About Eve as well as successfully adapting Shakespeare to life in Julius Caesar, Mankiewicz does a marvelous job of bringing this hit Broadway play to film and does it with style. Marlon Brando is perfect as Sky Masterson, even if he can't sing too well. He is the only actor who could pull it off perfectly wit his sheer coolness and clarity. Frank Sinatra is a wonderful singer, as expected, and does a good job of acting as Nathan Detroit. Jean Simmons is also very good as Sarah Brown and her scenes with Brando sizzle with great chemistry. All supporting actors do their part, especially Sheldon Leonard as Harry the Horse in a very funny bit. Still, Mankiewicz should be given most of the credit for bringing a fine musical in its own right to the screen in such a way that it feels authentic in many scenes but is still a story in its own world. All in all, Guys and Dolls is a great musical and works on many levels it normally should not have.