What scares you the most in horror films?

[Psycho Circus]

I don't like gruesome medical scenes, anything with eyeballs, throats and bugs.

[RCMerchant]

I don't like gruesome medical scenes, anything with eyeballs, throats and bugs.

I agree. Them surgery TV shows are too much.
I also dont like seeing kids killed. The scene in PET SEMATARY when Gage gets hit by the truck...dam. That freaked me out.

[Jack]

^ Agree with you guys.  Watching real-life surgery on TV creeps me out 100 times more than the most gruesome thing in any horror movie.  I just plain cannot watch that stuff.

[RCMerchant]

 The most wincing scene in the EXORCIST was when she was in the hospital...they did a tap and scan. Dam. I been there. Scary.

[InformationGeek]

What I can't see or see well.  The remake of Don't Be Afraid of the Dark did this well for me, at least until they showed the monsters up close.  I'm more terrified by what I can't see because the images my brain makes are far more scarier than what I see.  For a nonmovie and odd example (It's from an online show), Atop the Fourth Wall's The Entity.  You never see the monster/creature/it or anything of the like.  It's prescene is known by its static laugh, the camera breaking down, or characters getting attacked by it/being erased from existance.

Other favorite horror is more of a psychological horror, where you see characters breaking down and start to lose their minds as their world around them falls apart.  Perfect Blue did this well for me by also making the viewers start doubting what they are seeing since we begin to start seeing things through the main character's view.  Also, Higurashi's Curse Killing Arc was another good example, especially when you are not sure actually who was killed or even if someone was killed.

[macabre]

After waking up next to my wife for the last 18 years i find that i am immune to any horrors placed on the celluloid screen, although when i was young the spiral staircase did scare the s**t out of me.

[The Gravekeeper]

Isolation, as in the first bit of 28 Days Later, not the like every slasher movie out in the woods. There needs to be the possibility that you/the character are the last person alive. I guess to me that comes loaded with the fear of helplessness. You break a leg or get seriously ill in a scenario where there are other people, there's at least a chance that someone can help. Have that happen when you're essentially the last person on Earth? Enjoy your slow, agonizing, lonely death.

Distortions of the everyday. We know what to expect from the world immediately around us, so when something's off about something we're familiar with, it can be terrifying if done right. It's why anything ever falls into the Uncanny Valley.

And of course, loss of self. Zombies themselves aren't generally scary. The thought of becoming a zombie, of slowly losing your identity or of having something else snatch your body away from you, is pretty chilling.

[JaseSF]

The bleak hopelessness of some film noir movies and some urban crime films. Computer control and nuclear war has been terrifying in its fashion in Colossus, Threads, The Terminator, The Day After...but then that's non-horror films or are they?

In horror films, whenever it feels like you (through the eyes of the lead character) are losing control and the world turns to bizarre chaos making you question reality, your sanity, etc. - Jacob's Ladder, In the Mouth of Madness, Quatermass and the Pit, Lifeforce all did this pretty well.

[Criswell]

Honestly regular people doing horrible things is what scares me the most in movies.

[Hammock Rider]

I do not care for movies where people get possessed. The idea of something invading your body and your mind, no thanks. Watching people break down psychologically is also pretty scary.

[The Burgomaster]

For me, I guess it's paranoia and isolation.  INVASION OF THE BODY SNATCHERS is a perfect example.  You don't know who you can trust and you can't seem to get away to a safe place.  NIGHT OF THE LIVING DEAD is another good example.