From my days as Reviews Editor at the lovely (but pretty much defunct) comics-related website www.popimage.com. A list of what I considered required horror reading back in 2004. I can think of at least 10 other books that are equally as good that are out right now – especially the newer collections of Ditko’s Charlton work (particularly The Thing), half a dozen vertigo books, Alan Moore’s Neonomicon (excellent stuff), and maybe a couple David Lapham pieces (very much liked his Caligula). Oh, and manga-wise, Junji Ito’s Uzumaki.
So, yeah, this list is pretty old school, but I think it holds up nicely.