The Shortest Papers Ever Published (2016)
Although these short papers are fun, I think the most interesting papers are those that are both important and concise. One of my favorite examples is Josh Nash's proof of the existence of Nash Equilibria (which is a foundational concept in game theory and arguably won Nash a Nobel):<p><a href="http://www.pnas.org/content/36/1/48.full" rel="nofollow">http://www.pnas.org/content/36/1/48.full</a><p>It's less than a full page in the original journal.