Tom Hagen: I'm an attorney for the Corleone family. These men are private detectives hired to protect Vito Corleone. They are licensed to carry firearms. If you interfere you'll have to appear before a judge in the morning and show cause.
Michael: My father is no different than any powerful man, any man with power, like a president or senator.
Kay Adams: Do you know how naive you sound, Michael? Presidents and senators don't have men killed.
Michael: Oh. Who's being naive, Kay?
Clemenza: Leave the gun. Take the cannoli.
Michael Corleone: Fredo, you're my older brother and I love you. But don't ever take sides against the Family again. Ever.
Don Corleone: You talk about vengeance. Is vengeance going to bring your son back to you? Or my boy to me?
Sonny: What the hell is this?
Clemenza: It's a Sicilian message. It means Luca Brasi sleeps with the fishes.
Calo: In Sicily, women are more dangerous than shotguns.
Sonny: Goddamn FBI don't respect nothin'.
Michael Corleone: It's not personal, Sonny. It's strictly business.
Clemenza: Mikey, why don't you tell that nice girl you love her? I love you with all-a my heart, if I don't see-a you again soon, I'm-a gonna die.
Sollozzo: I don't like violence, Tom. I'm a businessman; blood is a big expense.
Vito Corleone: I'm gonna make him an offer he can't refuse.