The Descent (2005)

Written and Directed by Neil Marshall

Starring Shauna Macdonald, Natalie Mendoza, Alex Reid

KATY SAYS: This terrifying story about a caving expedition going horribly wrong is a long favorite of mine. Filmed entirely on a sound stage, the set work is so incredible you would think that they somehow managed to film all of this in a real cave. A medium amount of gore, turn off all the lights and enjoy the bloody fun.