Looking for mystery / horror of various forms
Off the top of my head, doubtless forgetting lots of very good stuff:
Books: The Loney, Andrew Michael Hurley; any M.R. James stories (most are available online since he's out of copyright); Devil on the Road, Robert Westall; The House on the Strand, Daphne DuMaurier; Carnaki the Ghost-Finder, William Hope Hodgson; The Secret History, Donna Tart.
Graphic fiction: Gideon Falls, any Emily Carroll (she's got a generous amount online, and is seriously one of the best horror writers out there - check out His Face All Red as a place to start...some things stay unanswered, and that just adds to it all), Broodhollow (webcomic, stalled but 2 books' worth done), Wytches, oh, and Harrow County, of course. Gen-rated horror is the best because with no shortcuts like gore every spook has to punch hard for what it does.
Films: Savagelands, The Endless, The Orphanage, Blair Witch Project...nope, that's all you're getting from my brain this late at night. Hope there's something in there you like!