A tabletop game that does Darkest Dungeon justice would be fantastic. Characters would have to be capable of fighting and exploring but who are completely physically and mentally vulnerable to the wear and tear of their journeys. It would require troupe-style play, and folks couldn't stay too attached to any one character for long. I have heard that Dungeon Crawl Classics can emulate this pretty well, and I read recently that the Torchbearer RPG is supposed to be getting some Darkest Dungeon materials, and if so, I will probably cave and pick Torchbearer up. If you haven't played the computer game, I highly recommend it.
The second media that I wish was an RPG is a fantasy novel setting:
The setting is a low(er) magic setting in which Magiere- a self-styled vampire hunter - travels from town to town with her half-elf companion Leesil, who poses as a vampire, who she "kills" in order to bilk the town out of a reward. Their world turns on its ear when their travels bring them close to a town that's *actually* infested by vampires, and they are convinced Magiere is coming for them.
Now, The Noble Dead (like Darkest Dungeon) isn't something I couldn't bend one of my favorite systems to (Savage Worlds comes to mind), but the same could be said for most licensed RPGs and we still buy them anyway, don't we?