Kazuo Umezu
Between the Orochi series, the Cat-Eyed Boy series, and his Scary Books, I am quickly becoming a fan. I didn't think I would, as the Orochi episodes tend to be pretty predictable, but I just can't help but love his work. The art, while admittedly dated, is gorgeous, and he is so good at setting up an atmosphere for horror. I recently read some of Left Hand of God Right Hand of the Devil, and it's pretty intriguing so far. If I can get my hands on his Scary Book #3, that's also on my To-Read wishlist.