Well, let’s see.
There’s this infamous moment from the 2008 Joker graphic novel:
And speaking of The Joker, the whole severed face thing from the New 52 has to be one of the grossest, goriest things that DC’s ever done:
Since I just mentioned it yesterday, here’s the beheading scene from Twilight #1, one of many, many stomach-churning, off-putting things about that book:
And as far as covers go, this is my choice for the single grossest/goriest cover that DC’s ever published: