For my money, it would have to be BAC. I just bought some of his stuff from BAC Comix, and it was worth every penny. He deserves some kind of award for being one of the pioneers of this community. Too bad he isn't a member of the Forum. Or is he?
I've always been particularly partial to the work of FTKL. He's always been one of my favorites, since the beginning of Tales from the Asylum, and I love his characters. It's a shame he doesn't do as much work nowadays, or perhaps I'm just not aware of it.
Mind you this just my humble opinion. There are many great artists out there. I would also just like to say again how much I will miss CB. Sorry to get all depressing and stuff. I just felt I needed to mention it.
I love the works of BAC, Ozzy and FTKL as well as the late CB. But my favorite artist has to be ShanE. When it comes to capturing looks of sheer torture, ShanE's got it down to a science. I love the shading and dark angles he uses. On a personal note, every story he's ever illustrated for me seems to have been plucked right out of my own head, the picture perfectly representing what I had in mind. His latest comic was sadistic, and that's a good thing.