I got to see The Woman in Black this weekend, and absolutely loved it. It was positively terrifying; I had goosebumps running down my arms the entire time. I had read the original novel by Susan Hill beforehand; the movie is not 100% faithful to the book, but the main premise remains intact, and I think it came out as a better movie for it. The setting simply drips with creepiness, and the camera work takes full advantage of this. The music is lovely (in a sinister way), and I thought the acting was pretty good.
If you enjoy a good ghost story, or want a scary horror movie that does not rely on gore or violence, then I highly recommend you see this one.