Now, a word of caution: this is my list, not your list. Be careful what movies you pooh-pooh, or can't believe I didn't include. These are part of my difinable criteria, and your own mileage will definitely vary. Also, and I really shouldn't have to say this, but Spoilers Abound. We're talking about movies that all of you should have had ample time to see. Don't blame me if you read something you'd rather not have read.
Number Five: American Werewolf in London--the attack on the moors.
4. The Ring--the creepy dead girl crawling out of the well.
3. The Thing--the Blood Test Scene
The first time I saw this, I nearly crapped my pants. "I thought you'd feel that way, Gary. You were the only person who could've gotten to that blood. We'll do you last." SCHREEEEEEEE!! I didn't see it coming, and neither did you. That whole movie really holds up, and in a film known more for its grotesqueries, the Thing-Blood jumping away from the needle is one of the best jump-scares of all time.
2. The Shining--the creepy twins
1. The Exorcist--the final exorcism
Since I can't stop you from disagreeing with me, go ahead an gnash your teeth in the comments section. If you think I'm overlooking a movie or two, speak up!