tokyo ghoul has shit art.
Personally, I find Tokyo Ghoul to be the best of both aspects. The story is dark, the characters are awesome, and so on. Another good one was Akame ga Kiru, which ended up bombing halfway through.
So I see your criteria is gore and shock value eh.
Personally I liked Death Parade better than Akame go Kill or Tokyo Ghoul. Parasite was better than both too. Noragami was good. Durarara!! season 2 got me the most hyped but I just love that guys work, his story telling is great. Hamatora and Re:Hamatora were good. Nobunagun was a fun anime too.
I'm sure it's just me since most people here seem to love them but after Elfen Lied and Deadman Wonderland I just can't get into an anime that's gory for gory-ness' sake like Akame or Tokyo or Attack on Titan. Maybe if they had better stories like Lied or Wonderland then sure, but it comes across as if they're being so graphic just so they can say "we're not for kiddies" even though the majority of the readers are teenagers and younger.
Tokyo Ghoul far from being only a gory thing. Judging something before you really know what it's about is so wrong in many levels.
Alone the dveleopment the main character gets in the series is above amazing. You can put 10 shonen Mangas together and add the development of their mc's together and they wouldn't come close to that.