The Blair Witch Project (1999, dir. Daniel Myrick, Eduardo Sanchez)
We saw this together without knowing too much about it except that the shaky cam, found footage style it was filmed in was making people sick. Quickly the movie was unsettling in its use of handheld cameras. It gave it a realism that made you wonder, if only for a second, that maybe the ad campaign was real and this stuff really happened. What also helps sell that idea is that the actors in the movie were all relatively unknown.
Casting unknowns in a horror movie is always a great move. It takes you out of the comfort zone of “oh they’re in this, they’ll make it to the end”. As if it wasn’t scary enough that the characters were out camping – gross – weird things start happening. The tension that these events builds up throughout the movie pays off in a great callback to a legend briefly mentioned earlier in the movie.