At times HOUSE OF LEAVES made my head (and my wrists) hurt, but I admit to enjoying the former sensation. The confusion and disorientation experienced by the reader (and paralleled by the characters) seems essential in successfully traversing Danielewski's semiotic Rubic's Cube of a novel.
It's an interesting, quirky experiment in ergodic literature, and while I admit I did not find it completely successful as a story, there is plenty of meat to satisfy genre readers, assuming one can identify the genre at all. Is it (Lovecraftian/cosmic)horror? A love story? A satire? Or all three? Whatever the case, I'm glad I read it and for the most part enjoyed the experience, but it is not one I'm in any hurry to repeat. When you find yourself for the tenth time spinning the book around like a DJ at a rave in order to read the upside down or sideways text, it's easy to get distracted by the gimmick, even when the crazy layout serves a very obvious purpose.
And yet, despite my problems with the book, when the story worked, it did so fabulously. Danielewski is a remarkable (and remarkably intelligent - which might go some way toward explaining his compulsion for non-traditional narrative) writer, and the story, when indeed it works, is astonishing.
It's a tough book to recommend, and I doubt there will be much middle ground here among readers. You'll either laud it as a masterpiece, or loathe it as an overhyped, gimmicky, and frustrating exercise in self-indulgence. With this book, it's hard to argue against both verdicts, which only adds to its mystery. I would at least recommend giving it a try. As a reading experience, it's certainly an unusual one, and that in itself warrants a look.