The Punisher MAX
Garth Ennis, Goran Parlov, and others | 2004 (MAX)
Marvel's resident gun-toting vigilante was always ahead of the curve as far as violence was concerned—especially during writer Garth Ennis's definitive eight-year run—but the adults-only MAX series cranked the dial up to 11 with stories like "Up Is Down and Black Is White," in which Frank Castle finds the man who desecrated his family's graves, drags him to the woods, and strings the guy's guts up like Christmas lights while he's still alive.
At one point, the Punisher blasts Wolverine’s face off with an Uzi, but the healing-factor-endowed mutant keeps coming. So Castle aims for the balls. No more coming for you, Logan!
