Napoleon Dynamite is like if Superbad was nothing but that scene of Michael Cera singing "These Eyes" by The Guess Who. Just 100% cringe, awkward interactions between the main characters. Like an inside joke that literally nobody is meant to get, even the people "in" on the joke.
Honorable mentions: Nacho Libre (similar in its randomness), Wayne's World (a classic) and Road Trip (similar to Superbad in its frat humor).