They're just... of a time, let me put it that way. Like, a lot of the language, decor, acting style, themes, will seem completely alien to you Like, I just re-watched The Breakfast Club recently and was like, "You know, some of this doesn't hold up!"
You shut your damn mouth when you're talking about The Breakfast Club! That's still an all time classic and yes, it's definitely an 80's movie but nothing wrong with that :) I'd also recommend avoiding ET. That movie is garbage. Add Jaws to the list if you haven't seen that.