I don't think I could do a top 5 list.
Just too many I like and I would want to keep changing them around or put them in sub genres and so on.
With that said.
I bring up a movie or two that I did not see listed, may have missed it, that as a young child scared me or had specific scenes that scared me. Probably not scary at all if I were to watch them now.
The single scariest memory from a movie was the floating vampire boy at the glass door with the fog behind him in Salem's Lot. At that time that scared me and I was screaming...DON"T LET HIM IN.
If I sat and watched the original now I would probably laugh but at the time it was new and even on network tv...it was scary to a young kid.
Gargoyles - I think that was the name of the movie. I only remember small sections of it but gargoyle like creatures abducting people and taking them to a cave and one of the lead Gargoyles had crazy contacts that looked like devil or demon eyes.
https://www.youtube.com/results?search_query=gargoyles+movie
Looks like you can watch it free on Youtube....and just from glancing through a bit of it, it looks super goofy now...but as a young kid...scary. Came out in 72 and I was born in 70. I have had to seen it a few years after it originally came out but I bet it was not too many years.