What is a the scariest movie ever?

I want a movie that will actually scare me. I was literally laughing during Paranormal Activity because it was hyped so much. Movies like Saw and Hostel, I think are just a stupid waste of fake blood. And old school movies like Nightmare on Elm Street, Carrie, The Exorcist, Friday the 13th, Halloween, Pet Cemetery are just look too cheesy now. I want to be disturbed to the point where I can't sleep. Please don't give me lame answers like Orphan, Drag Me to Hell, Hills have Eyes, The Texas Chainsaw Macre, House of Wax, Wrong Turn. I have seen all the big name horrors and they just don't do it. If some one can give me a such a movie you will have my greatest respect and of course ten points.