There's nothing more I can say about this book that hasn't been said by hundreds, if not thousands, of other readers and critics. It's a classic for a reason.
A haunted house story to beat all haunted house stories, with the added bonus of Shirley Jackson's sublime prose. As an example I submit the opening paragraph, which in my opinion, are some of the best in all of literature.
"No live organism can continue for long to exist sanely under conditions of absolute reality; even larks and katydids are supposed, by some, to dream. Hill House, not sane, stood by itself against its hills, holding darkness within; it had stood so for eighty years and might stand for eighty more. Within, walls continued upright, bricks met neatly, floors were firm, and doors were sensibly shut; silence lay steadily against the wood and stone of Hill House, and whatever walked there, walked alone."
I happily re-read this for this square: