For those of you who liked "On the Waterfront" I'd recommend checking out some of the involved actors other films as well. Karl Malden (Father Barry) had a long run and impressive career and has a large selection of films to choose from. One of my favorite films of all-time is Sidney Lumet's "12 Angry Men" which has Lee J. Cobb (Johnny Friendly) playing a hothead once again. Much like this film there is a slew of terrific actors in 12 Angry Men. You have a young Henry Fonda, Martin Balsam, Ed Begley, Jack Warden, Jack Klugman, E.G. Marshall, etc.
If you don't immediately recognize some of the names look them up and I guarantee you've seen some of their other films.