For me, watching horror films is like climbing on a roller coaster. If the movie is powerful, I am afraid, I cover (like in my childhood) my face with my hands and my heart goes a thousand miles per hour, and, ultimately, I live them at maximum.
Although overall they shock me easily, there are few horror movies that last forever in my memory. This is a very personal list. A list with those movies that terrified me sincerely and that I will never forget.
Notice to sailors: not all these movies belong, strictly, to the horror genre.
I hope you have happy nightmares with these films. And if you want to give me your point of view, it will be a pleasure for me.