Cannibal Holocaust is good, but i think that the poltergeist or the shining is a little bit more edgy

Theres only two possible ways you can go with this one, the Poltergeist or The Shining, trust me

Honestly, horror movies arent too scary. Theres only three movies I can even remember being scared watching, and they are The Strangers, The Poltergeist, and Saw 3. There are some other scary ones, but these are the only I can think of that really made me not want to sleep that night