This is about the Marvel Cinematic Universe, otherwise known as Earth-199999.
The 20th Century Fox and Sony films are not part of this. For example, the X-Men films are part of Earth-10005.
A lot of Marvel fans seem unhappy that Marvel doesnāt own all of the rights to all of the characters, and so not everyone is included in the same universe together. Personally, I like it this way. It helps lend some variety to the stories and characters. I love the MCU movies and t.v. shows, but I also love much of the X-Men movies.
As explained below by @anon73430903, those characters are not owned by Marvel any longer, and so the universes are totally different. Which is part of the fun, imo!
My only argument here truly for this list is number one has to be Iron Man 1. Without that film none of the others come to being. That one set the tone. And it was a great flick on its own. Truly. It showed how to do a good quick down and dirty back story-becoming a hero within a short time frame.
When comparing movies and franchises you have to separate smaller casts vs ensemble casts. Things like Agents of Shield, Avengers, and Guardians are wholly different animals to Iron Man, Thor, and Captain America. Its almost unfair to compare the character development of Captain America TWS and that in Avengers.
So I would always put Iron Man 1 on top for breaking through the wall and doing it so well. Almost perfectly. A well defined villain with understandable motivations. A developing hero who finds his voice. Supporting characters who do just thatā¦SUPPORT. The entire movie is centered and well focused on Tony Stark. As it should be.
I would put CA:TWS right after it. Because it really was as you say a great plot-line and story ripped from classic real life issues from a by gone era and dropped into our current real world version of that. Different timeā¦same problems. Love this flick and again I would argue it has like IM1 a well defined main hero finding his voice and path, a well defined villain with clear motivations, and a supporting cast who SUPPORT.
after those two, I think its a toss up based on perception and tastes.
Iron Man 1 also did a huge favor to the Marvel cinematic universe by creating interest in a very uninteresting character. I knew very few people outside of hardcore Marvel fans who gave a crap about Iron Man before the movie came out; even casual superhero fans I know had zero interest in seeing a movie about an alcoholic womanizing millionaire who fights crime in a robot suit. But Jon Favreau and Robert Downy Jr. made Tony Stark a star (if not THE star) of the Marvel universe and opened up Marvel to do pretty much anything from that point forward.
