The Descent (2005) is a greatly traumatizing horror flick for anyone who's even mildly claustrophobic. Even if you are not, you might be after watching it.

The Exorcist (1973) is still a movie most people do not want to watch alone in a dark house, despite being over 40 years old.

Hellraiser (1987) is strange and frightening, even when judged among the other movies on this list. It shows what happens when your skinless undead boyfriend escapes a hell dimension and you have to kill people to bring him fully to life.

The Host (2007) is a monster movie from Korea about a possibly man-made or mutated entity that kidnaps children, and one father's attempts to rescue his child.

28 Days Later (2002) is the movie that gave us all fears of a viral zombie outbreak.This basic theme would later be repeated several times over in following zombie films, but this is where it all started.

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