(Mr. McDonald played himself in the mob movie “Goodfellas,” and one of his lines in that film to a mob associate’s wife (Lorraine Bracco) — “Don’t give me the babe-in-the-woods routine, Karen” — became memorable in its own right.)

Even mob guys have mirrored behavior from the “Godfather” films on occasion, as in 1977 when prosecutors said a man acting on behalf of the Colombo crime family was trying to secretly stash bribe money in a Long Island restaurant. He chose the same place where Michael Corleone finds the gun hidden for him in “The Godfather”— a toilet.

“Just like in the movies,” an undercover agent exclaimed on a wiretap after pulling the cash from the commode.

Though lines from other films have become part of the American lexicon — “I’ll be back” (Schwarzenegger, “The Terminator,” 1984) — few have had the enduring impact of the Godfather series, said Kenneth Dancyger, a professor of film and television at New York University’s Tisch School of the Arts. He attributed that to the unique combination of skilled scriptwriting, acting and directing as well as to the film’s insights into an American brand of power and corruption.

“At the heart of it,” Professor Dancyger said, “is family and honor and trying to protect the family from a corrupt world, which is what Don Corleone is trying to do.”

The scripts for the first two Godfather films were a collaboration by its director, Francis Ford Coppola, and Mario Puzo, the author of the book by the same name.