1935 musical comedy
Plot: Poncho, Lefty, Karl, Stinky, Shifty, Bimbo, Gordo, and Jacko Marx destroy a night at the opera.
When ranking the Marx Brothers movies I've seen, it would be Duck Soup at the top followed by everything else. A Night at the Opera is consistently cited as one of the best if not their very best, and I can understand why. The story is easily the most cohesive, the pacing is much better, and their are some classic bits. I don't think those classic bits are as uproariously hilarious as some of their others, and this one does suffer from that 1930's need for comedies to have endless and bland musical numbers. And while I do always enjoy watching the obligatory Harpo and Chico musical numbers, this one isn't their best. Still, I'm just nitpicking. This is not only a great 1930's comedy, it's (as the poster says) the funniest picture ever made.