I haven't found a lot of 'horror' so I'll be listing everything I find - even before reading it myself, so take the ones I label unread with a grain of salt.
Also remember Horror is subjective, not everyone will find the same things scary.
Supernatural is technically a subgenre of horror but I think I'll keep those elements separate UNLESS the story actually gives scary vibes! No Edward Cullen up in this list haha.