AFI #014 Humphrey Bogart as Sam Spade from The Maltese Falcon (1941)

Polhaus: [lifting the fake falcon] It's heavy. What is it?
Spade: The, uh, stuff that dreams are made of.
Polhaus: Huh?

- Humphrey Bogart as Sam Spade from The Maltese Falcon (1941)

The bolded line is ranked #14 in the American Film Institute's list of the top 100 movie quotations in American cinema.