For you movie buffs out there, I want to find the scariest movie ever, your opinion?

I need help finding the ultimate scary movie, I really want to scare the heck out of my friends. I recently saw "Funny Games" the 2007 scene-for-scene remake of the Austrian Film, I thought that was the scariest, I mean the SCARIEST MOVIE EVER!!! I thought it made "The Exorcist" look like a funny movie. I literally wanted to leave the room, it was that scary, and I like to finish movies. Anyways, I'm looking for a scary movie that's both physically and psychologically painful to the mind and all else. "Funny Games" fit that discription. In your opinions what is the scariest movie you all have ever seen? Go on and get your friends and collaborate this one please! Alright, I look forward to hearing your responses! Thanks in advance!