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 thought Alien 3 was popular. I'll give you an unpopular opinion: Alien 4 was pretty okay and I’d watch it again.
Predator 2 is an overall beloved movie, just like Terminator 2.
Is it a popular opinion that people didn't like Predator 2? Nearly everyone I know loves it. Not as much as the original mind you but they still love it and so do I.