I used to say Casablanca was my all time favorite, but now I may like Play It Again, Sam a little better.

The Hudsucker Proxy; The Private Life of Sherlock Holmes; One, Two, Three (1961); His Girl Friday; Galaxy Guest; Young Frankenstein, Airplane; Ghostbusters; WarGames; Vertigo; Network; Clerks; Arthur; Twelve Monkeys; It Happened One Night; The Wizard of Oz; Guardians of the Galaxy; The Iron Giant; Romancing the Stone; Raiders of the Lost Arc, Star Wars; and The Empire Strikes Back are some of my other favorites.