I just bought and watched this two classic gangster flicks from the 1930s. Both are very entertaining, but I think THE PUBLIC ENEMY is the better of the two films.
LITTLE CAESAR - Edward G. Robinson stars as Rico (aka "Little Caesar"), an ambitious hoodlum who works his way through the ranks of the underworld using intimidation and murder. A great, old-time talkie with tough, rapid-fire dialogue. A must-see for gangster movie fans.
THE PUBLIC ENEMY - James Cagney stars as Tom Powers, a streetwise kid who graduates from petty street crimes to bootlegging and eventually murder. This is the movie with the famous "grapefruit in the face" scene. It also includes some scenes I thought were a bit "shocking" for its time, including a scene where it is very directly implied that Cagney, while heavily liquored up, has sex with a seductive woman. This movie co-stars Jean Harlow and Joan Blondell. The final scene is somewhat chilling and disturbing.