In the lead-up to Avengers: Endgame I decided to do a thorough re-watch of all the Marvel Cinematic Universe films, reviewing them as I went (I skipped the TV shows, as those weren’t really part of the story). Below are the review links.

1. Iron Man
   It all seemed like just another superhero film; a second-string Marvel hero little known outside of comic book fandom, like so many other such characters that got their own films in the 2000s, when people were already starting to make noise about whether comic book movies were on their way out.

2. The Incredible Hulk
   
   All in all, The Incredible Hulk is definitely a step down from Iron Man. It’s certainly entertaining, stylishly filmed, and has very real strengths, but it makes a number of key missteps, especially with the villains, and there are a lot of moments where the script seemed rushed or incomplete.

3. Iron Man 2
   
   So far, the first Iron Man was an all-around excellent superhero film. The Incredible Hulk had a lot of issues, but was still a fairly strong entry. And Iron Man 2? It’s a huge flaming mess.

4. Thor
   
   After three relatively grounded science fiction stories, Thor takes the MCU in a starkly new direction with world-hopping high-fantasy tale of gods and kings. It’s really kind of amazing that it works as well as it does.

5. Captain America: The First Avenger
   
   All in all, Captain America: The First Avenger is an uneven, but fairly strong entry in the burgeoning MCU. It struggles with too much story to cover and several major missteps, but is carried on the strength of a genuine inspirational hero and an (almost) unabashed adventure style.

6. The Avengers
   
   In a word, The Avengers works across the board, when it so easily could have been a disaster (one only needs to consider the Justice League film for an example of how badly it could have gone wrong). More than that, it is a landmark in cinema history.

7. Iron Man 3
   
   …this film is a gigantic mess, and unlike Iron Man 2, the individual parts can’t even stand on their own as far as they go. It’s like the director simply walked in, took a solid premise, and decided to make it all into a giant practical joke for his personal amusement without caring a whit about the characters, the story, or the franchise.

8. Thor: The Dark World
   
   Ultimately, The Dark World is not bad, exactly; it’s entertaining enough, and it continues many of its predecessor’s strengths. But it’s weighed down by a very lazy script, several bad storytelling decisions, and one of the most forgettable villains in any superhero movie. The result is probably the most thoroughly ‘average’ of the Marvel films; relatively solid entertainment crafted onto a heavily flawed story.

9. Captain America: The Winter Soldier
   
   I’ll be honest; Captain America is my favorite hero in the MCU (and one of my all-time favorites), and Winter Soldier is pretty close to my ideal of a Captain America film.

10. Guardians of the Galaxy
    
    In short, Guardians is one of the best films in the series thus far; a thoroughly satisfying stand-alone space-opera-comedy with a unique personality and tone. More than anything, it shows that the MCU was still willing to be creative, take risks, and deliver on pure entertainment.

11. Avengers: Age of Ultron
    
    In summary, Age of Ultron is a big step down from its predecessor; it tries to tackle too much, fails to settle on what it wants to be about, and makes a number of key mistakes along the way. But that still leaves a lot of room for an extremely entertaining and thrilling superhero adventure full of iconic moments.

12. Ant-Man
    
    There are objectively better films in the MCU than Ant-Man, but for simple, largely-self contained entertainment, featuring a good story, great characters, hilarious comedy, and a lot of crazy creative action, you really can’t do much better.

13. Captain America: Civil War
    
    I’m calling it: Civil War is the best film in the MCU, and one of the best superhero films of all time. The story, the characters, the dialogue, the action, everything works, and works spectacularly.

14. Doctor Strange
    
    Overall, Doctor Strange is a very strong film. The prologue is a problem, the villain is kind of dull, and there are a few other gaps…but it’s extremely creative, very entertaining, and anchored by a great lead character with a strong, consistent arc, and all leavened with some of the best visuals we’ve seen yet.

15. Guardians of the Galaxy Vol. 2
    
    Guardians 2 is kind of an odd film; it reaches further than its predecessor, and in some ways outdoes it, but it also fails more. So, overall I’d rank it below the first film, but some parts of this one are stronger than anything in the first one.

16. Spider-Man: Homecoming
    
    It’s frustrating; they have probably the best live action Spider-Man yet, but they dropped the ball on building his story and his world. It’s still worth seeing…but for a series that has been doing such great work with almost every other Marvel hero, it’s a real disappointment to see them fumbling the Big One so badly.

17. Thor: Raganarok
    
    I can’t call it a bad film, and it’s entertaining enough going down, but I don’t like it. The whole premise and conception of the film seems all wrong to me, sacrificing tons of potential storylines and characters for the sake of a mish-mash of a fairly standard story…The execution is generally pretty strong, if uneven, but it’s the execution of a failed premise, so it can never be particularly satisfying.

18. Black Panther
    
    The word I would use to sum up Black Panther is ‘lazy.’ For whatever reason, the filmmakers appear to have put almost no effort into the actual story and characters of this movie. They didn’t think anything through or ask even basic questions about their own plot….It’s an utter mess of a film, one of the worst of the MCU, and a complete waste of a fantastic character.

19. Avengers: Infinity War
    
    This film is incredible. They are juggling so many different elements, so many different characters, continuing on from so many different storylines that merely to be watchable would have been an achievement. But it’s more than that; it’s indisputably one of the best superhero films ever made.

20. Ant-Man and the Wasp
    
    Like it’s predecessor, it’s just a very nice, very fun, feel-good adventure. The romance is sweet and not over-done, the characters are lovable, the action is thrilling and not too violent…and the visuals are spectacular and creative. These two films together probably represent just the most sheer fun of the whole MCU.

21. Captain Marvel
    
    I never thought it would happen, but Captain Marvel beats Iron Man 3 by a country mile; it’s by far the worst film the MCU, not only because it’s terrible in itself, but because it proceeds to singlehandedly devastate the franchise continuity, re-contextualizing classic scenes to mean something completely different, and all in the name of artificially elevating a thoroughly repulsive character to a status she doesn’t deserve.
22. Avengers: Endgame
    
    They brought it in and stuck the landing, imperfectly, and not without a stumble or two, but satisfactorily, creating a single, glorious tale told over the course of over twenty films. Whatever happens from now on, whatever future films may bring, we at least have this.

Conclusion
In this world, the MCU has been a fortress of solid storytelling and iconic heroism in mainstream entertainment. With a few exceptions, they have been tales of people striving to do the right thing despite the obstacles and despite their flaws, while the fantasy elements magnify and illuminate their characters. That is, they serve the same function as classical mythology, or fairy tales; passing on timeless truths via tales of wonder and excitement.