3. 'Monty Python and the Holy Grail'
British comedy troupe Monty Python were near the peak of their popularity when they decided to shoot a film parodying King Arthur's quest to find the Holy Grail during a break between seasons of their BBC sketch show. Their first film, 1971's And Now for Something Completely Different, was merely a collection of sketches. This time around, they aimed far higher and stuck to a single premise. The result was an absolute masterpiece that immediately attracted a fiercely devoted plot. It even lead to a Broadway musical adaptation in 2005.