Out of all the horror movies Ive ever watched, its my absolute favorite. It's truly one of the best "horror" movies you will ever watch. The dread is so well done. The jump scares are well paced and actually add to the story. It's fantastic and lingers with you for awhile.
My other favorites of all time, is the first tape from V/H/S, the original Texas Chainsaw Massacre, Nope, The Poltergeist, The Ring, Juon (White Ghost, Specifically).