[Reincarnate]

This (start scrolling down to read): http://comic.naver.com/webtoon/detai...d=350217&no=31

In terms of movies, though, I guess:

It
The Thing (Carpenter's)
Alien
Event Horizon
The Shining
The Grudge
The Grudge 2 (Japanese version, starts out with the car ride etc -- some corny stuff in there but also some really disturbing shit)
Martyrs
American Psycho (disturbing)

This scene from Fire in the Sky scared the everliving fuck out of me as a kid:

Although if you really want disturbing/scary shit, IMO you have to get into the books because your imagination will always fill in the gaps with the most horrific shit