By "little known," I mean aside from classics like Dracula or Frankenstein or The Hunting of Hill House, or more contemporary bestsellers like Stephen King or Peter Straub or Joe Hill.
Lately I've been reading some great horror books published by a smaller press called Valancourt Books, which has a lot of undiscovered clasics. My favorites so far have been The Elementals by Matthew McDowell, Burnt Offerings (which is perhaps better known because of the famous movie) by Robert Marasco, and some very creepy novellas and stories by Robert Westall (collected in Antique Dust, The Stones of Muncaster, and Spectral Shadows). I also have read some great and very unsettling short stories by the mid-century British writer Robert Aickman re-issued from Faber & Faber. Anything along these lines to recommend? I prefer unsettling, creepy stories to gory ones.