In History of the World Part I, during the Rome scene, Josephus (Gregory Hines) is walking along and Oedipus is walking in front of him wearing sunglasses and shouting "Give to Oedipus! Give to Oedipus!" Josephus walks up behind him and Oedipus puts his hand back and says "Say Josephus!" Josephus (slapping the hand) replies: "Say MotherF#$@er!"
I didn't catch it on my first viewing, but Oedipus is the "original" "mother$%@##$"
Has anyone seen Juno, Donie Darko, My Cousin or History? There are more famous one-liners in 30 minutes of Airplane than in all these others combined - and EVERYONE knows them. Yes, the Harry met Sally line is famous - but its the only one from the movie. The only movie that comes close to Airplane for one-liners is Caddyshack. Its in the Hole!
"Airplane!" is one of my all-time favorites, and is certainly one of the very funniest films ever made. But as for the funniest line... I would give that to "The Thin Man", where Nick and Nora are reading the newspaper accounts of the break-in at their apartment, and discussing how many times Nick was shot. As this is an even more-classic film than "Airplane!", rent it and see for yourself.
How about Planes, Trains, & Automobiles: "You play with your balls a lot." "I do NOT play with my balls." "Are you kidding? Larry Bird doesn't do as much ball handling in one night as you do in an hour!" "Are you trying to start a fight?" "No. I'm just saying you fidget with your nuts a lot." "You know what would make me really happy?" "Another set of balls & a couple of extra fingers?"