Guardians of the Galaxy

Essential, and the easiest standalone watch in the franchise. It is set entirely off Earth, involves none of the existing cast, and a viewer can start here with no context at all.

It was also the biggest gamble Marvel took. The characters were obscure, two of the five were a tree and a raccoon, and the budget was enormous. James Gunn's answer was to make a comedy about grief with a mixtape in it: the film opens on a child in a hospital corridor being handed a Walkman, and every needle drop afterwards is that scene's echo.

The ensemble is the achievement. Each of the five is introduced through what they are running from rather than what they can do, and the prison sequence gives them all a job so the audience learns their competences by watching rather than being told. Dave Bautista's Drax, who cannot process metaphor, is the funniest thing in Phase Two.

The villain is a man with a hammer and a grudge, which is the standing complaint and is largely irrelevant. The Knowhere and Xandar designs gave the franchise a visual register it had not had, and the final dance-off is as silly and as earned as anything here.