A while back I got the bug to start watching truly scary movies. I have yet to find a single one since I began my quest.
Jump scares don’t count, for my purposes. They’re cheap startles, and IMO cheating (although see below). Gore doesn’t do it for me - that’s just gross, or possibly creative. Dramatic tension can be effective, and can certainly be a part of a good movie experience, but it doesn’t scare me.
There were a couple of movies that scared me as a kid, but almost nothing I’ve found seems to be able to do it as an adult. As a little kid, It Came From Outer Space really got to me - it was the basic implications of a life-threatening, contagious disease (that turned you into slime!) that did it for me then. Close Encounters had a few scary scenes, to my young brain. But very little since then has really done it for me.
As an adult, just about the only movie I can recall that I found scary, where at least I could feel the hairs on the back of my neck rising and the juices of my imagination started flowing, was Marble Hornets (the first season). What worked there? It was that we were dealing with a new, and kinda psychologically plausible, monster with little lore behind it. The frightening bits were mostly centered around that vague feeling you sometimes get, when you’re all alone, that you’re somehow being watched - and in Marble Hornets, you can sometimes catch a glimpse out of the corner of your eye of the guy that’s watching you! The format - “found” footage, chopped up into brief youtube segments definitely contributed to the verisimilitude. And being able to watch it on the computer, alone, at night, made it more intimate.
I would love to find another piece of work that gave me that same set of feelings, but I fear I never shall.
As a last note, I was truly tweaked when reading this Korean horror comic online. Again, the intimacy of being alone at night and looking at it on my computer screen contributed to the experience. Also, it being foreign and the language incomprehensible to me added to the sense of alienation and oddness.
But what really did it for me was the unexpected moment where the comic FUCKING COMES TO LIFE!!! That bit served as probably the only non-cheap jump scare I will ever experience.