I don't really watch horror anime, but I love horror manga. Probably because japanese-produced anime tends to blur/black-out any sort of major gore, which takes me out of the moment as far as viewing. It's less of an issue in the manga for me due to it being less censored in general or at least easier to ignore for my brain for some reason. Plus, I enjoy the black and white of most manga vs the full color of most anime, it somehow makes the art more interesting to me.