Urusei Yatsura: The Shougaibutsu Suieitaikai

This Special has all the characters from Urusei Yatsura back together again for a "school is an obstacle course" episode.
The jokes rely on two things:
1. putting twists on typical high school sports
2. each character's bit
The story-boarding is dynamic, animation is good and generally fluid which lends to the comedy.
It's mildly interesting to see Urusei Yatsura animated with in a modern digital style but all it really is, is a nod to the fans of the original series.
Nothing special beyond that.

Actually it might be worth seeing the opening minute for the Ranma, Inuyasha and Urusei Yatsura crossover if that is your type of thing.