The gangster made his first appearance in American films in D.W. Griffith's silent film The Musketeers of Pig Alley, but it would take Josef Von Sternberg's 1927 film Underworld to kick the gangster film into high gear and then Mervyn LeRoy's 1931 Little Caesar to give the American gangster his voice.

Little Caesar was the first gangster film with sound and the first in a cycle of gangster films from Warner Brothers. The films represented a shift in the studio's focus toward more gritty and realistic storylines, and soon branded the company as "The Gangster Studio." Little Caesar, with an energized title performance by Edward G. Robinson, along with the sensational sounds of squealing tires and staccato machine gun fire, was a great box office success and inspired Warners to pursue more of these stories that seemed ripped from the headlines.

Warners made smart use of its talent. The studio system was strong and companies had to rely on the pool of talent they had under contract. MGM had more glitz and glamor, and actors that could be more accurately described as stars. But Warners had a group of actors -- in addition to Robinson they had James Cagney, Humphrey Bogart, George Raft and John Garfield -- who were not your conventional leading men. These guys could play characters on either side of the law but they always brought a gritty sense of having come from the street. So whatever side of the tracks their characters were from -- gangsters, criminals, cops, lawyers -- they came across as real and often sympathetic.

The Warners gangster films peaked in the '30s and '40s, although some stragglers can be found in each subsequent decade, most memorably in 1967 with Bonnie and Clyde. In 2013, Warners paid tribute to its gangster history with Gangster Squad.

Here is a list of the best Warner Brothers gangster films from its prime era, 1931-1949. It does not include works like I Am A Fugitive From A Chain Gang or They Made Me A Criminal, which do not specifically feature gangsters. These gangster films can also be seen as the harbingers of film noir, a genre that would dominate the '40s with its seductive moral ambiguity.

1. 'Little Caesar' (1931)

Director: Mervyn LeRoy

Stars: Edward G. Robinson, Douglas Fairbanks Jr., Glenda Farrell

Edward G. Robinson kicks off the gangster film in stellar fashion. He gives us Rico, a fireplug of a hoodlum who works his way up from the bottom to a position of power. It's a quick rise and even quicker fall, and all that Rico craves is more power. He dismisses loyalty, trust, and friendship as weaknesses and therefore has no one to turn to at the end. He's a monstrous little man who's nothing without a big gun but Robinson makes him riveting.

The film came out when Prohibition was still in effect, the Depression was hitting America hard, and gangsters appeared to be running rampant. Although Rico had no redeeming qualities, the film was seen as glorifying violence and the gangster lifestyle. At a time when so many had so little, the money and excess displayed by gangsters like Rico had an undeniable appeal even if only as a fantasy. But no matter what anyone thought, Robinson's Rico assured the gangster a permanent place in American pop culture.

Most memorable line: "Is this the end of Rico?"

2. 'The Public Enemy' (1931)

Director: William A. Wellman

Stars: James Cagney, Jean Harlow, Joan Blondell

James Cagney gives us a gangster "torn from the headlines." His Tom Powers was inspired by real life Irish-American gangster Charles Dion O'Bannion. Like Rico, Powers is drunk on power but he is moderately more sympathetic. The film delivers one of the most iconic and memorable screen moments of all time when Cagney's gangster gets so annoyed with his girlfriend played by Mae Clarke that he smashes a grapefruit in her face. The scene caused women's groups to complain but there's no denying the scene is brilliant. Cagney, like Robinson, got catapulted to fame with these gangster roles. The end of this film is as stunning and brutal as it was then. And trivia note: the machine gun attack on Tom Powers used real bullets and an expert marksman.

Most memorable line: "There you go with that wishin' stuff again. I wish you was a wishing well. So that I could tie a bucket to ya and sink ya."

3. 'G Men' (1935)

Director: William Keighley

Stars: James Cagney, Margaret Lindsay, Ann Dvorak, Robert Armstrong

Cagney's immense likability combined with the criticism Warners received for glorifying gangsters probably led to this film about government men or "G" men tracking down criminals. Cagney was firmly on the side of law and order this time, but his performance was still fueled by the same rapid fire delivery and streetwise energy as his Tom Powers hoodlum in The Public Enemy.

Most memorable line: "You haven't had an attack of brilliance lately. Why don't you try guessing?"

4. 'The Petrified Forest' (1936)

Director: Archie L. Mayo

Stars: Leslie Howard, Humphrey Bogart, Bette Davis

A waitress, a hobo and a bank robber walk into a diner... Okay that's not a joke but it is the premise for this film adaptation of Robert Emmet Sherwood's play. Leslie Howard and Humphrey Bogart originated the roles on stage. Warner Brothers was fine with pretty boy Howard reprising his role but they wanted their hot new star Edward G. Robinson in Bogart's role of criminal Duke Mantee. Howard, however, insisted on Bogart. The role made Bogart a hot commodity and he would later name one of his children Leslie after the man who helped him to his first big break. Bogart is great in the role of the weary gangster on the run.

Most memorable line: "You know the story. Most of my life in jail; the rest of it dead!"

5. 'Angels with Dirty Faces' (1938)

Director: Michael Curtiz

Stars: James Cagney, Pat O'Brien, Humphrey Bogart, Ann Sheridan

Cagney crosses back over the tracks to play a young thug named Rocky who gets sent to reform school and learns how to be a criminal. Meanwhile, Rocky's friend Jerry (played by Pat O'Brien) becomes a priest. Both men are looked up to by the kids in the neighborhood but for very different reasons. When Rocky gets sent to the electric chair, Father Jerry asks him not to appear all cocky but to appear repentant so that the kids who looked up to him will rethink their admiration. But Rocky makes no promises. When he is taken to the chair he goes "yellow," but we can never be certain if it was an act to please his friend or how Rocky really felt. The film showcased the Dead End Kids who made their debut in United Artists' Dead End the year before.

Most memorable line: "You'll slap me? You slap me in a dream, you better wake up and apologize."

6. 'The Roaring Twenties' (1939)

Director: Raoul Walsh

Stars: James Cagney, Humphrey Bogart, Priscilla Lane, Gladys George

Warners takes a look back to the '20s for this star-studded film chronicling the rise and fall of Eddie Bartlett (James Cagney). Bartlett comes back from World War I to find no employment. He eventually turns to bootlegging, but tries to avoid violence. Bogart plays his partner who doesn't quite have the same restraint. A great cast.

Most memorable line: "You want the Brooklyn Bridge, all you gotta do is ask for it. If I can't buy it, I'll steal it."

7. 'Invisible Stripes' (1939)

Director: Lloyd Bacon

Stars: George Raft, Jane Bryan, William Holden, Humphrey Bogart

The gangster film was starting to wane and grow stale. Raft and Bogart play cons who get out of prison and Raft wants to go straight, but Bogart doesn't. Raft wants an honest life to make his mom (played by Flora Robson who was actually 6 years his junior) and family proud. Fun, but nothing special.

Most memorable line: "What do I want with another girl, Ma. I've got you, haven't I?"

8. 'Brother Orchid' (1940)

Director: Lloyd Bacon

Stars: Edward G. Robinson, Humphrey Bogart, Ann Sothern, Donald Crisp

Warners tried something new with this crime story that was more a comedy as mobster Little John Sarto (Robinson) attempts to reinvent himself as a monk. A fresh take on the genre, but not enough to fully revive it.

Most memorable line: "Oh, I'll get him all right. This is Little John Sarto."

9. 'High Sierra' (1941)

Directed by Raoul Walsh

Starring: Humphrey Bogart, Ida Lupino, Arthur Kennedy

The '30s were the best era for the Warners gangster films but the '40s saw a fitting close to the cycle with a pair of films that no longer pulse with the raw energy of the early films but rather display a bleaker more nuanced tone. Bogart plays Roy 'Mad Dog' Earle (shades of Duke Mantee here). Earle gets broken out of prison for a job but the robbery results in a murder and Earle is forced to go on the run. He ends up in the sierras and in a standoff with cops. The film provides a kind of elegy for the gangster films of the '30s as it transitions the genre into the more complex film noir that would define the '40s. Bogart also lays the groundwork for his noir anti-hero, a man who may not respect society's laws but one who has his own sense of integrity.

Most memorable line: "Yeah, he squawked. I should have taken care of him when he followed me out. Look at the tag they hung on me? 'Mad Dog' Earle, them newspaper rats!"

10. 'White Heat' (1949)

Director: Raoul Walsh

Stars: James Cagney, Virginia Mayo, Edmond O'Brien

Cagney makes the most of his last gangster role, Cody Jarrett, a crazed killer with a mother fixation. Cagney, nearly two decades after playing Tom Powers in The Public Enemy, is still in rip-roaring form, a tightly-wound dynamo just waiting to explode. As with High Sierra, White Heat had the darker hues of film noir coloring its gangster tale. A classic, and Cagney atop an oil refinery tower that blows up is a brilliant punctuation mark to end the Warner Brothers gangster cycle of films.

Most memorable line: "Top of the world Ma!"