There are a lot of fictional worlds out there that are engrossing, engaging and yet places you really wouldn't want to actually live. Anything after any sort of apocalypse, for instance. Or Westeros. But if you're in a world with Zombie, or Dragons, or even Zombie Dragons, there is the comfort of distance, a comfort that this isn't, and can't be this world. I think that in many ways that is one of the big selling points of SF/F fiction, the distance that lets you explore the potential horror of alternative lives knowing that it can't happen to you. The thrill of crime fiction is different, of course, because it's set in this world, where terrible things can, and do happen all the time, with hardly a Zombie Dragon in sight. And right at the dark, terrible end of Crime fiction is Noir, and my favorite Noir writer has to be James Ellroy.
