Monsters Inc. has been one of my favorite Pixar movies. Being that MU is a sequel, I didn't expect to be wowed -- just entertained. (Better to come in with low expectations so that I am not disappointed when a sequel is not as good as the original.) However, I was profoundly moved by this film.
Technically, MU is a prequel. It chronicles how Sully and Mike W. met at university, where they majored in Scaring. They both failed out of the major and became antagonists: Sully was cocky about his scaring abilities -- his father was a famous scarer, and frightening was easy for Sully -- and Mike was more of a scholar, hoping that knowledge would give him an edge.
Unfortunately, Sully could not get by with coasting on his natural talents, and Mike had absolutely no "scare" in him, so they banded together with a fraternity of "losers" in a scare competition, and Mike made a deal with the dean -- who had failed them both out of the Scare major -- that if they won the competition, she would let them back into the major.
Two-thirds of the film is about how Mike trains the "rag-tag groups of misfits" into a top scaring team, and this is all fairly enjoyable, but it is not really until true crisis hits that this movie takes a turn towards intensity and a deep exploration of how a friendship is forged. I won't spoil anything, but I will say that the finale was gripping and emotional, and I left shaken up and convinced that Pixar is the only animation studio that truly knows how to create a story in which character trumps animation and silly jokes.