I have more of a pool of favorites that trade in and out depending on if I've watched them recently, but I'll be basic and put the original Suspiria as one that usually floats around the top. The dreamlike atmosphere is just so immersive.

It's been awhile, but I was partial to Insidious.

Martyrs (original)

A Quiet Place

so many great ideas in this thread to build an October watch list!! for me, my faves have always been the exorcist (og 70's), the conjuring, and the scream movies because they're fun!

The Insidious and Conjuring series are good and I always went on dates with my husband to see them as they came out so they are extra special to me

The Lost Boys isn't really scary, but it is one of my favorite movies. For movies that actually scared me, Poltergeist still holds the top spot.

The Conjuring Insidious Halloween series I love Jamie lee curtis