Never been one to get scared by horror movies. I just can’t get the buy in necessary to feel scared for the characters. However, the closest to traditional horror I can think of that really was effective was Green Room. It’s intense in its loud parts and tense in it’s quiet. It’s realistic modern cult horror.

If you expand the field out a bit and look to more of a ‘leaves you with dread about reality’ effect, ‘When the Wind Blows’ is very affecting. It’s animated but the story is quite realistic.