Recommendations for some Adult Anime

[Little Woodsman]

Trying to stick to ones not previously mentioned in the thread:

Bubblegum Crisis OVA's
AD Police files
Any Lupin Movie
Any City Hunter Movie
Utawarerumono
Tsukikage Ran, Carried by the Wind
Black Magic M-66
Mermaid Forest

I'm putting the following titles in a separate category because they are *seriously* depressing.
You will want to remove all the sharp objects from the room before viewing these.
Heck, for a couple of them you will want to remove all the *blunt* objects from the room before viewing.

Ruroni Kenshin OVA's (very different from the tv series)
Grave of the Fireflies
Who's Left Behind
Voices of a Distant Star

There are actually a couple of others that I'd recommend in terms of intellectually mature themes, but
from what you said in the OP, I really don't think they are what you are looking for. {shrug}

 

[deserteagleeye]

Appleseed
Fate Zero
Black Lagoon
Mirai Nikki
Darker Than Black

Monster

I was a bit dissapointed in its ending but the journey itself was pretty good.

 

[Talaris]

An adult anime is quite subjective, as a lot of shows that don't target the seinen market are still great for adults, and from a western point of view, the amount of anime specifically for children is in the minority.

Anyway, here are a few I believe have a mature narrative to them:

Steins;Gate - Time travel drama
Shiki - Mystery horror
Umineko no Naku Koro ni - Murder mystery/Horror themed sister show to Higurashi
Sayonara Zetsubo Sensei - Eccentric comedy, but with a lot of themes/topics e.g philosophy/politics only an adult would appreciate.
Mirai Nikki - Psychological action horror, and one of my all time favourites.
Wolf's Rain - Adventure/Drama, a beautiful and sad story about 4 wolves and their journey. I would say it's too dark and depressing for younger audiences.

 

[Defeated Detective]

Serial Experiments Lain
Texhnolyze(from the same creator as SEL)
Legend of the Galactic Heroes
Sword of the Stranger
Now and Then, Here and There
Kino no Tabi
Bokurano
Mushishi
Kaiba

Kaiji
Akagi
One Outs
Welcome to the NHK

I did a huge disservice forgetting to add those 4.

 

[Angie7F]

Ok, how about Steins Gate? And Chaos Head?