well, that's a difficult assessment for the marvel franchise as it has become of late. They do a really well job doing the good thing comics did. Thus:
There is one big story-line over all marvel movies
There are story-lines for each character/component (such as Iron Man, Thor, The Guardians of the Galaxy)
There is, so far in my experience, a closed story-arc in each movie. So it's not like e.g. LotR where 3 movies make up one story - it's rather 3 movies, 3 stories that progress the character
There are, in the meanwhile, a number of mashups that started with The Avengers movies and have no…