Viewing conditions and state of mind are everything.

Rating: 4/10 (1 August 1999)

When there were only(!) 90 posting about this film there were only seven that did not range from from "really scary" to "best film ever made!" All seven disliked the film and four viewed it on video. I just came from a midnight screening that was packed with college students. I have to guess, but judging by the boos, hisses and only moderate applause, it was not seen by 90% of these viewers as "the scariest movie ever made."
Viewing conditions and state of mind are everything. This (very well edited) film does not come to you, you have to go to it, almost literally. If you want to be scared, see it in a movie theater. Unlike most fright films, try to go when the theater is almost empty. Crowd reactions will take you "out" of the film. And I mean this in the best sense of the word, be naive. Any critical thought applied to The Blair Witch Project blasts through it like a searchlight through a tissue. What you will see then is a very thin excuse for a film.
I would like to recommend that you find and rent a copy of "Cannibal Holocaust," the original "found footage" horror documentary. Unfortunately, you probably won't find it, and if you did, the fake (human) and real (animal) butchery would definitely put you off. However, for the strong of stomach, that is a film that is not only disturbing in broad daylight, but also disturbs to instruct. Two things that The Blair Witch Project cannot claim for itself.
In short, if you've never gotten over your childhood fears and are still afraid of the dark, even just a little, under the right conditions, Blair Witch is for you.
Otherwise, skip it.