The Blair Witch Project by Daniel Myrick, Eduardo Sánchez. Three film students go missing after traveling into the woods of Maryland to make a documentary about the local Blair Witch legend leaving only their footage behind.
Cabin Fever: "A group of five college graduates rent a cabin in the woods and begin to fall victim to a horrifying flesh-eating virus, which attracts the unwanted attention of the homicidal locals." Has some of the best movie characters ever.
Evil Dead - Five friends head to a remote cabin, where the discovery of a Book of the Dead leads them to unwittingly summon up demons living in the nearby woods. The evil presence possesses them until only one is left to fight for survival.