Here's my rankings of the ones I've seen so far.  Some memories may be a little foggy so I will need to rewatch a few.  I've actually started a ranking project of ALL comic book movies but that will take quite a while to complete.   

1. Guardians of the Galaxy (10/10)
Huge fan of this movie.  Great fresh feel, funny and charming.  Bring on GotG 2!

2. Iron Man (10/10)
This film was amazing when it was released.  The suit looked incredible and Downey Jr. was expertly cast.  Definitely in the discussion of best super hero movies of all time.

3. Captain America: The Winter Soldier (8/10)
I quite liked this one though I remember it being very long. I'd like to watch it again.. 

4. Ant-Man (7/10)
Enjoyable film.  Paul Rudd was a little underused from a comedic standpoint but it was a solid movie overall

5. Thor (7/10)
Chris Hemsworth was well cast. Movie had some funny moments with the dialogue. I like this movie.

6. Avengers (7/10)
I need to do a rewatch on this one... I don't really remember too much except for the Chitauri attacking New York and lots of chaos.

7. Thor 2 the Dark World (7/10)
About on par with first one. Pretty good

8. Avengers 2 (6/10)
Ultron was a bit weak.  But it was a great realization of Hulkbuster.

9. Captain America: First Avenger (6/10)
Chris Evans was well cast... but the movie was a bit hard for me to get through.  I would like to try it again.

10. Iron Man 3 (6/10)
Had it's moments. Need a rewatch.

11. Iron Man 2 (5/10)
Don't remember getting much enjoyment from this one.

Still need to see The Incredible Hulk