Avengers Endgame did feel like an event (and it was, don't get me wrong).
But I'm old enough to remember Spider-Man 2 and The Dark Knight. Went to both of those screenings at the midnight premieres (back when midnight screenings were a thing).
The Dark Knight midnight screening in particular, though ... Man. Not even Endgame was able to recapture that. The entire audience was entranced and amazed by the storytelling. You could hear a pindrop at all of the right scenes, people cheered, applauded, and gasped at all of the right scenes, etc. The energy in that theater that night was that everyone there knew that a movie classic was happening in front of our eyes.
And when I went to see Spider-Man 2, that is the first and only time I saw people literally give a standing ovation to something in the middle of the movie-- when Spidey stopped the train.