The Godfather Part II
A rarity for Oscar month: a sequel (and through multiple flashbacks, simultaneously a pre-quel) to the original movie, and more than any other, the reason every other successful Hollywood movie ever since gets sequelled, usually to death - because other directors lack the abilities of Coppola, and/or the strength of story to begin with.
After its predecessor nearly being ruined by meddling management the first time by a hostile studio, in the second movie the director was given a free hand, and thus shooting two completely different narrative storylines was more easily accomplished. Carrying the modern saga, Pacino is brilliant, and for the section on prehistory, an actor named Robert DeNiro was selected. Also featuring Lee Strasberg, who provides a great film speech in a memorable scene.
Best Picture, Best Director, Best Adapted Screenplay, Best Supporting Actor (DeNiro), Best Art Direction, Best Music for Dramatic Score