Gotta go with the Dark Knight Trilogy. The Dark Knight films felt like events to me. They just felt special to watch. I dunno, it's kinda hard to describe. It just felt like I was seeing something more than just a film, those movies really resonated with me. Even Rises which everyone either hates or is indifferent towards, and is maybe the weakest of the trilogy, yet is maybe my favorite of them. I still rewatch that one all the time. The Captain America movies were fun action popcorn flicks to me, nothing beyond that. I still haven't really seen First Avenger. Winter Soldier was really good but the Nick Fury death fakeout really took me out of the movie for whatever reason, I think just a general tiredness with Marvel films where a character "dies" except they don't. Civil War was maybe the closest feeling I've gotten to seeing an event like the TDK trilogy, like you're seeing something really special.