In the film, "You've Got Mail," what movie does Joe Fox say answers all of life's questions?

In the 1998 film, "You've Got Mail," the two main characters, Tom Hanks as Joe "NY152" Fox and Meg Ryan as Kathleen "Shopgirl" Kelly, are part of a scene where they are discussing a popular 1972 crime film directed by Francis Ford Coppola and produced by Albert S. Ruddy. It is the "Godfather." Joe tells a needy Kathleen why it is a very influential film.

Joe says: "The Godfather" is the I Ching. "The Godfather" is the sum of all wisdom. "The Godfather" is the answer to any question. What should I pack for my summer vacation? "Leave the gun, take the cannoli." What day of the week is it? "Monday, Tuesday, Thursday, Wednesday...."

Joe has pointed to the "Godfather" to say that it answers all of life's questions. In 1990, the U.S. National Film Registry of the Library of Congress publicly said that the "Godfather" was "culturally, historically, and aesthetically significant" and ranked number two as the greatest movie in U.S. cinema.