Superman II

Essential, and which version you watch is a genuine decision here, not a footnote. Richard Donner shot the first and second films simultaneously and had completed most of this one when he was removed from the production. Richard Lester reshot a large share of it, and the 1981 release is the result: lighter, jokier, with slapstick in the Metropolis battle and a different ending.

In 2006 a reconstruction was assembled from Donner's footage, screen tests and his intended structure, released as the Donner Cut. It restores Brando, replaces the time-reversal ending that Lester had reused, and is tonally continuous with the first film. It is also visibly a reconstruction, with test footage standing in for scenes never completed. Most people should watch the 1981 version first and the Donner Cut if they care.

Either way the film is strong, and it is the first superhero sequel to work out that the second film should take something away. Clark gives up his powers to be with Lois, in a scene with a machine and a decision that cannot be undone, and then finds out what has arrived while he was human. The three Kryptonians are the right antagonists because they do exactly what he could do and have no reason not to.

Terence Stamp's Zod is bored, patrician and completely uninterested in anybody's resistance, and the diner scene afterwards, in which a powerless Clark is beaten by a trucker, is the most memorable thing in the Reeve films.