Absolutely amazing series! Probably the best show of 2010. Every episode was suspenseful. It gets extremely scary and quite violent at times, but if that doesn't both you, then WATCH NOW!!!
By far the best horror anime- builds up a great atmosphere and is genuinely creepy, haunting, and thought-provoking. It's a slow-burn, but there's no filler in all 24 episodes of the show. The OST is phenomenal as well, and helps to build the mood. Though it may not appeal to everyone, if it's up your alley, it will stick with you for a long time.