I've enjoyed all of the MCU films, to varying degrees. I'm going off memory, because I've only re-watched 4 or 5 of them.
Fun but not great:
22. The Incredible Hulk (Ang Lee's film is flawed but more interesting, and my go-to Hulk origin - plus Eric Bana looks more like Mark Ruffalo haha!)
21. Thor: The Dark World
20. Captain Marvel
19. Iron Man 2 (love the briefcase suit up scene)
Fun and pretty good:
18. Avengers: Infinity War
17. Guardians of the Galaxy Vol. 2
16. Avengers: Age of Ultron
15. Ant-Man and the Wasp
14. Thor: Ragnarok (a bit tonally off for me - also, the thing that bothers me the most in the MCU is Thor not showing any reaction to the death of the Warriors 3)
13. Ant-Man
12. Iron Man 3
11. Thor
10. Captain America: Civil War
9. Avengers: Endgame
8. Spider-Man: Homecoming
Movies I loved:
7. Captain America: The Winter Soldier
6. Black Panther
5. The Avengers
4. Doctor Strange (the only solo hero in the MCU with a memorable musical theme imo)
3. Captain America: The First Avenger
2. Guardians of the Galaxy
1. Iron Man (people say RDJ gave the character humor, but I say check those Micheline/Layton back-issues, because Tony's humor has been well-established since at least the late 70's - I will say RDJ gave the character snark and a bit of a manic personality - his performance as Tony is one of the best of his career)