The 'Godfather' trilogy was an American gangster film directed by Francis Ford Coppola, with actors such as al Pacino and Joe Pisci. The series had been widely acclaimed since its release and was regarded as one of the representative works of gangster films. The Godfather trilogy was regarded as a classic mainly because of its profound social significance and plot tension. The movie told the story of a gang family, revealing the power struggle within the gang, family inheritance, moral degeneration, and other topics. It also showed the historical changes of American society and the complexity of human nature. The narrative skills of the movie were also excellent. Director Coppola used a non-linear narrative structure to divide the story into multiple chapters, allowing the audience to enter new plots as the story developed. This way of narration not only increased the tension and suspense of the story, but also made the film more profound and complicated. In addition, the actors of the 'Godfather' trilogy also performed very well. The image of the godfather played by Alpacino was deeply rooted in the hearts of the people, showing the majesty and charm of the leader of the gang family. Joe Pantoliano played the godfather's younger brother, Vito, showing a smart, witty, and responsible character. The performances of these actors also made an important contribution to the success of the film. To sum up, the Godfather trilogy was regarded as a classic because it deeply reflected the complexity of American gangster culture, social history, and human nature. At the same time, it also showed the wonderful performance of the film production skills and actors.