Guardians of the Galaxy Vol. 3

The group finally learns where the raccoon came from, and it is worse than anybody guessed.

It is the darkest of the three and the only one whose subject is cruelty rather than family, told through flashbacks that most of this run would not have had the nerve to show.

It is also a proper conclusion, which is rare here: every member of the group finishes somewhere, and the film lets the ending be an ending.