This is a well-made horror movie based on a supposedly true story. This movie proves that it doesn't take a lot of gory scenes and jump-out-of-the-dark in-your-face scare tactics to make a good horror movie.
But although it is good horror movie, I would not consider it the best. It lacks originality. There are many similarities in this movie as there are in others of the same genre.
You have been warned!