Guro, the thing most of us know and love to hate.
While it may be fucked up beyond all comparison, it's actually decent to read, providing that it actually has some form of storyline, like Toukyou Akazukin....
One to avoid is Hell Season, as that is probably the most disgusting things I have EVER read.
While Guro may be classified as an ero style art, it does have some good features about it. Never a shortage of blood that's for sure.
Although...