Please don't list this on a work's page as a trope. Examples can go on the work's YMMV tab.
Nightmare Fuel: House on Haunted Hill (1999)
The scene where Melissa finds herself videotaping a ghostly vivisection in an empty room, and then senses something behind her. She turns, sees a shadowy figure peer around a corner way down the hallway, and in an eyeblink it's right there in her face, teeth, blood and all.
The scene where Steven Price discovers that another character's face and the insides of his head are missing (this discovery is accompanied by Ominous Latin Chanting, of course). To make matters worse, he sees the unnaturally twitchy ghost doctor taunting him with his large bloodied knife on surveillance footage. See the scene here: http://www.youtube.com/watch?v=aYhhxqkd0Vw
The nightmare sequence in which Steven Price is in the "saturation chamber." First, his head is tightly wrapped and dunked in water by twitching creepy ghosts. Then, he sees a beautiful young woman submerged in water who starts bleeding from the mouth before revealing her Nightmare Face (which consists of smooth-ish skin where her eyes and nose should be and a giant gaping mouth: ◊) while screaming at him. Finally, he is exposed to his wife holding his (still alive!) severed head while laughing evilly. See the creepy scene here (NSFW because of brief nudity): http://www.youtube.com/watch?v=nI7w-5S2rrA
Steven Price's wife rotting to nothing by "the Evil."
The final shot at the end of the credits, showing the characters devoured by the "Evil" in a nightmarish scene right out of Vanacuts depraved "Home movies", suggesting they're still trapped in an endless hell within the Asylum. Even the opening credits are creepy.