Films unique in how they scare the viewer?

I want to watch a horror film that's really scary. It's hard to explain, but 9 times out of 10 I watch a horror film and it just doesn't frighten me at all. It doesn't even feel eerie most of the time. I've seen all the popular ones and even out of the ones I found the scariest, I still wasn't really phased by them. I've gone through dozens of "scariest films ever list" and it's either a non-scary one I've already watched or a shock-factor "disturbing" one that gets by on taboo themes instead of actual scares, that I have no intention of watching.

The scariest films I've seen so far have been "Martyrs", "Barbarian" and "Audition". No others have really scared me.

It probably sounds like I'm showing off but I really want something new aside from the cookie-cutter "supernatural" ghost films I see most of the time, and films that use gore and jumpscares as their main scare tactics. This is also a place to discuss what makes horror scary since I don't want to make this post just about me. I want other people in similar situations to me to get good recommendations, maybe.