Avengers: Age of Ultron

Trying to build a shield around the world, Tony Stark builds something that decides the world would be safer without them.

The villain is the consequence of the heroes’ plan rather than an outside force, which is the most interesting thing about it and also why it is uncomfortable to watch.

It is the crowded one. It introduces characters, plants arguments the next film will fight over, and carries an Infinity Stone into a new body, all while running a full plot of its own.