Magnolia: It's arguably the best movie ever made, and it has what is without question the best ending, not only in movie history, but for all time. For as long as people make movies, no movie will ever have a better ending than this one.
Big Lebowski
Blood Simple
Barton Fink
Fargo
Miller's Crossing
Raising Arizona
Bubble boy; it got poorly reviewed, and did terribly at the box office, but I've yet to see a film that made me as happy as when I watched that. 😀