Thor: The Dark World

Skippable, and it is the one the franchise's own films make jokes about. Thor: Ragnarok opens by dismantling its ending, and Avengers: Endgame returns to it for comedy. Even Marvel treats it as a shrug.

The cost of skipping is one plot point: the Reality Stone leaves Asgard here and is in play later, which Infinity War restates. There is also a change of occupancy on the Asgardian throne at the very end, which Ragnarok explains in its first five minutes.

The film is not incompetent, it is anonymous. Christopher Eccleston plays an ancient elf under so much prosthetic and processed dialogue that no performance survives, his motive is darkness, and the plot runs on a convergence of realms that functions as a reason for portals to open where needed. The director has since spoken about a difficult production and a cut he did not control.

Two things work. The sequence where Thor and Loki escape together, bickering, is the first glimpse of what their relationship becomes. And a funeral scene, with lanterns going out over water, is the best-looking thing in the first two phases.