No disrespect to Brando, Pacino or De Niro, but Jimmy Cagney is hands down the greatest gangster actor to ever appear on the big screen. He appeared in classics like "The Public Enemy," "Angels With Dirty Faces," and "White Heat," solidifying his rep as the best that ever did it. When I was a kid I used to watch his movies at my aunt's house on the weekends. I could recite a lot of the lines and I would stand in front of the mirror trying to imitate his stone-cold mannerisms. He wasn't the biggest or the strongest, but he definitely was the baddest.