The Shining - It gets more disturbing every time I see it. The soundtrack, Jack's sudden bursts of rage, Danny's terrified faces when he's seeing things (what a great performance from a kid who only acted in this and a tv movie!), the rivers of blood, the twins, the rotting woman in the bathtub, the creepy Lloyd and the chilling Grady... Even when contrasted unfavourably to the book (and I don't think it's that bad in comparison, just a different story being told) it's still a masterpiece.