Monty Python and the Holy Grail

Terry Gilliam and Terry Jones's Monty Python and the Holy Grail opened in 1975, the first full Python feature and the only one made with no outside pressure to behave. Its investors included members of Pink Floyd and Led Zeppelin, who had tax-shelter difficulties to solve. It won the Hugo Award for Best Dramatic Presentation in 1976 and has never been out of popular circulation since.

King Arthur (Graham Chapman) and his Knights of the Round Table are dispatched by God on a divinely commanded quest for the Holy Grail. On the way they hold a constitutional debate with an anarcho-syndicalist peasant, fight a duel with the Black Knight (whose limbs are removed one by one without the slightest effect on his fighting spirit) and reach the Cave of Caerbannog, guarded by a killer rabbit. The cast (Cleese, Idle, Palin, Gilliam, Jones, Chapman) play approximately twenty roles each, and the low budget shows everywhere, much to the film's advantage.

It became the source for Spamalot, Eric Idle's musical adaptation, which won the Tony for Best Musical in 2005 and has toured continuously since. The Holy Hand Grenade, the argument over African and European swallows, the Knights Who Say Ni: these have become cultural reference points in their own right, and they have outlived most of the films of their decade.

Why it's an Editor's Pick: It is the most-quoted comedy film ever made, and a primer on what British absurdism could do once it stopped trying to be respectful. Almost fifty years on, it is still funnier than 95% of the comedies released since.