" is dark and gritty.
" is dark and occult. The protagonist is called Arucard and for a good reason.
" has dark,depressing and bitter sweet stories. It's basically an anime version of (arguably) the best Japanese novels ever written.
" is another dark and gritty anime. I personally liked how the story unfolded, it felt like an old-school play.
"The Count of Monte Cristo
" is the alternate universe anime version of the (french?) play/novel(?) of the same name.
", which is touted as being the goriest scenes in anime.
" and it's sequel
. A good contender in terms of gore with the above. It also has some of the best animation I've ever seen.
", a dark and philosophical sci-fi.
"Kara no Kyoukai
", a dark anime consisting of 7 films. So the animation and stuff are excellent (cause you know, film = highbudget).
", you'll probably be confused the whole way through but when you reach the end your mind will equal blown.
I assume you're a fan of sci-fi, if so you'll really like "Memories
". It also has black comedy.
", violent and gore filled. Has awesome action. Consists of six 45min long eps.
", it's a thriller. Has arguably the best story of any anime.
", contains paranoia and excellent music
"Seikimatsu Occult Gakuen
", contains occult stuff, as the title states.
", a work of art painted in blood. Nuff said.
", shows how the robots came to power. Contains metaphorical buttrape (for the humans).
Oh and for teh lulz, "Detroit Metal City
". It's a comical take on death metal.
Another one for the lulz since you're into politics and all that jazz, "Hetalia Axis Powers
", it's a comedy.
And the stuff the others recommended.