Well, that was fun
I’d drop the Xmen Films and add Logan.We have a similar top 10. I'd add in X2 and Days of Future Past, but I may be biased as I was much more of an X-Men fan back in the day than Avengers etc.
My top 9 superhero flicks would probably be, in no particular order: X2, X-Men: Days of Future Past, Avengers, Iron Man, Spider-Man (Tobey Maguire), Superman, Man of Steel, Batman (1989), Dark Knight.
Not sure which film to slot in as the 10th - there are a half a dozen candidates.
And Fantastic Four. /joking!
For me, the best superhero movies are simply classic movies. They aren’t competing with Thor 2, they’re competing with the likes of Goodfellas, Aliens, Ghostbusters, and Star Trek Ii. Dark Knight makes that list, but I don’t think any Marvel flick does.