I'll go first. Mine is that I can't stand the Deadpool movies. They are self aware and self referential to an obnoxious degree. It's like being continually reminded that I am in a movie. I swear the success of that movie has directly lead to every blockbuster having to have a joke every 30 seconds
I saw them when they came out (and remember how I LOVED them) and rewatched the first one last year. It did not age as well as I thought it would have.
I liked the first one. Got super bored with the second. Never watched the third. I feel like the first one should have been the only one. It was a fine stand alone film.