Monty Python and the Holy Grail (1975)

Monty Python and the Holy Grail (1975) redefines medieval parody with its absurdist humor and shoestring budget of just £229,000, which is 10% less than the average cost of a 1970s comedy feature. Grossing over $5M worldwide—a 21.8x return on investment that outperforms #6 The Philadelphia Story's box office multiples—the film holds a 97% Rotten Tomatoes score and launched the Tony-winning musical Spamalot. Its legacy as a cult classic endures, with fans still quoting lines decades later.