Vox has ranked all the Marvel movies, and since I don't agree, I want to do my own ranking. This will be a quick one.
1. The Avengers
About as close to perfection as you can come with an ensemble action movie.
2. Captain America: The Winter Soldier
I just love this movie and I think it's crisp and brillant in what it does.
3. Captain America: Civil War
That one was a blast, too. Really, the top three spots could be arranged in any order and I'll sign on.
4. Iron Man
Really good first and second acts, but the third act struggles because the villain doesn't connect at all and the final fight is...meh.
5. Guardians of the Galaxy 2
Ok, now I'm cheating, haven't seen this one yet, so I'll take Vox at their word.
6. Avengers 2: Age of Ultron
Better than its reputation, this movie really wins out because of the relentless focus on the human cost and ethical issues.
7. Guardians of the Galaxy
This movie was a fun-fest from start to finish.
8. Iron Man 3
I like the Manadrin-reveal more than many people, and the middle part of the movie is exceptionally strong. The finale suffers, once again.
9. Captain America: First Avenger
Once again, strong first and second act, but villain and third act are real doozies and the supporting cast is dropped like a hot potato.
The scenes in Asgard are great, but the stuff in the little town in the desert is too corny for my tastes and and the giant robot thing is just yawn-inducing.
11. The Incredible Hulk
This movie also suffers from a bland end-game baddie. As long as the guy is a soldier, he's interesting enough, but the monster fight doesn't catch on at all, and the casting is off as well, with little chemistry between the main leads.
12. Iron Man 2
Yeah, well, that's one a structural mess. Marvel's first baby-steps at building the MCU, and it shows.
13. Thor 2
This is also all over the place, and they didn't seem to have known what to do with the characters other than "we need a second Thor with Loki in it".
The first Marvel movie to really leave me cold. Not a bad movie, but I was bored.
15. Doctor Strange
The first Marvel movie I actually disliked. I found the writing atrocious, the story forced, and the tricks didn't sell me enough on the small screen to overlook all these issues.