While Hughes' first screenwriting assignment for the National Lampoon team (Class Reunion) didn't exactly earn him many plaudits, his second film for the comedy publication helped launch his career properly.

Vacation has its origins in the short story that got his foot in the door of the Lampoon mag - a tale based on a real family trip back in the 1950s.

Harold Ramis brought the movie to life and it provided the perfect vehicle (pun entirely intended) for Chevy Chase to indulge himself as the increasingly frustrated Griswold family attempts to drive to Wally World.

Wacky yet warm and witty to boot, Vacation still stands as a classic comedy.