The Greatest Show on Earth (1952)
Considered the worst movie to ever win a Best Picture Oscar by many of the people who write for this blog, this Cecil B. DeMille circus drama is an insomniac’s nightmare—it’ll make you want to sleep more than anything else in the world, but will piss you off just enough to keep you awake.
The Greatest Story Ever Told (1965)
Bet you didn’t know that Jesus was Swedish, did you? Long, boring and terrible, but still worth watching just to enjoy the hilariously inappropriate celebrity cameos. If you can’t quote John Wayne’s only line in this movie, you probably don't belong on this site.
This Jan Michael Vincent live action Disney flick actually isn’t that bad, but it turns out that there aren’t that many movies with the word “Greatest” in the title, so some unassuming film was bound to suffer. Life’s unfair sometimes. That said it’s the only movie of the four that’s so obscure I couldn’t find a decent image of the poster for it.
The Greatest (1977)
This biopic starring the legend himself is 100x better than Ali, but that says far more about how much Michael Mann fucked up one of the most compelling stories in American 20th century history than how good this flick is.