The slow moving, Lovecraftian horror of this series continues to bewitch me. I actually had to stop reading this book in order to ground myself. I needed a break from the lyrical language spinning through my head. And my favorite thing, each of these novels is self-contained. Oh yes, they all deal with the threat of Area X, but they each handle the mystery so differently. And you definitely get an idea of what Area X is with each story, though you get a larger idea if you've read each novel.
One of the things I really love is the lack of names. And the closer you get to Area X the less of a person and more of a thing, as defined by your name, you become. It definitely adds to that unknown horrific quality of the novels.