The Birds.
I was terrified of The Birds as a kid and once when my daughter was a teen we rented it on a visit to my mom’s house. We both told her how great it was. In these days of CGI it was cheesy and not scary at all! We all laughed and talked about how time and technology change things!
There was one movie with Lon Chaney and Vincent Price about vampires that was so scary I couldn’t sleep afterward though.