Ignoring the marketing hype that preceded it (which was actually a great marketing plan) and judging the final film on its own merits, The Blair Witch Project was a very effective horror film. I appreciated the way TBWP maintained a steady level of suspense without resorting to a big "monster reveal" moment. I also enjoyed the ambiguity of the film's conclusion. BTW, I only just recently caught "The Curse of the Blair Witch" special, which was a Sci-Fi channel promo, and was surprised to find myself being spooked by it! Never thought a promo would get my imagination to wander like that!
....and get some water for billy!"