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
Different strokes for different folks, I guess. I think it's one of the greatest films ever made because I watched it, not because someone told me it was.
But seriously, 95% of the "classic" movies deemed so important are just not that good. They might have been remarkable for some reason at the time, but from a contemporary perspective, they're often boring, long winded, and generally not interesting.
It's the same with books. Some people decided at some point which books are considered "good" and everyone just has to eat that or be considered stupid. Can't speak for other languages, but I think it's extremely suspicious, that in Germany the "canon books" are almost all from a rather short timeframe, which just happens to coincide with 19th century nationalism.