I love the original Japanese horror films that many popular American films were based off of and Ju-On is no different. It's great and unnerving. Unlike newer horror films, they focused more on the environment and the immersion than on cheap gore and kills.
Ju-On is number 5 of my top 5 Japanese Horror films. Not a small feat. A very creepy trendsetter that left an impression on many directors to come. A much more cerebral experience than most western Horror, I recommend it.