The gangster movie transformed into dark epic—and, more important, into a metaphor for every family’s dysfunction, and a lot of America’s, too. The burnished darkness of Gordon Willis’s cinematography sets an unforgettable tone. The grandeur of the acting (Brando, Pacino, DeNiro among others) gives it a curious nobility and the multigenerational narrative has the power to move us to terror, pity and, occasionally, bitter laughter. Maybe it is, as some have said, only a pop masterpiece. But a masterpiece it surely is.