Rainbow: Nisha Rokubou no Shichinin
Shinsekai Yori
Kaiji
Shigurui
Ergo Proxy
Gungrave (if you haven't seen it, skip the first epsiode (trust me, the first episode is literally the same episode as one later on, its much better to watch from the beginning of the actual story) its a masterpiece in my opinion).
Higurashi
Aoi Bungaku Series
Alright thanks. Already saw Ergo Proxy and Shinsekai Yori and especially like the latter.
I'm going to check them out as soon as i finish the Monotogari-series.
@.access:
Only anime? If you are willing to try manga, I recommend Dragon Head.
At the moment i'm more in the mood for anime, but i'll keep it in mind if i feel like starting a new manga, thank you.