20. Captain America: The Winter Soldier: The Nick Fury Twist
Even now, more than ten MCU films later, The Winter Soldier is still the best film in the MCU.
A masterful mixture of exhilarating action movie and thought-provoking political thriller that unfolds in a flawlessly-crafted world full of fleshed-out characters, meaningful relationships and genuinely frightening villains, The Winter Soldier is an incredible movie and The Dark Knight of the MCU.
The Winter Soldier isn't a film with any particularly obvious flaws, since it really is a great movie, but one element that really doesn't work is the Nick Fury plot twist. Nick Fury faking his death was a plot twist so obvious it was kind-of painful and it didn't add anything to the movie either.
Samuel L. Jackson is still great and this is probably his single best MCU performance, but it's a shame he was involved in this meaningless twist. Since it was so predictable and pointless, it's mysterious that this was even left in.
It doesn't detract from the film and also led to a wonderful Easter egg: Nick Fury's fake grave has '"The path of the righteous man..." Ezekiel 25: 17' on it, which is a delightful nod to Pulp Fiction, but other than that this plot twist is pretty jarring.
Drop the twist. It would've meant more Samuel L. Jackson in the movie and given how fantastic an actor he is, more of him is never a bad thing.