You'll have to excuse me and some of the other proponents of 'National Lampoon's Animal House' if we seem a little defensive about the movie. That's because it's often not recognized as the superior comedy classic that it is. Instead, too often it is lumped in with the multitude of inferior films that it inspired, which is totally unfair.
Some of the conventional wisdom about 'Animal House' is absolutely right, though. John Belushi does give a bravura performance that is reminiscent of the great comics before him like Chaplin, Keaton (Buster, not Michael), the Marx Brothers, etc., and he does it with a wonderful economy of words. His character of "Bluto" Blutarsky is often emulated and imitated but many times the persons doing so have no idea what it was that made him and his performance so great.
Tim Matheson as "Otter" and his other frat house buddies were also prototypes that were much imitated too, and again often without success. Otter was the quintessential smooth talker, always working an angle on everybody, especially the ladies. When a woman tells him that his lovemaking wasn't that great, he cocks his head, points a finger at himself and mouths the words, "not great?" in mock disbelief. Before Tom Hanks got "Big" he made a career out of playing this character. Also John Vernon set a standard for straight men with his portrayal of the beleaguered Dean Wormer, plagued by his "zoo fraternity."
Not all of the movie's humor aims low, by any means; some of it is quite sophisticated. (Yes, you read it right.) The screenwriters and director John Landis did a great job evoking Kennedy-era America and they found a lot to laugh at. This comedy is an unqualified classic by the simplest definition-- it makes you laugh, long and loud.