I was wondering if anyone had an anime that required you to think. don't say deathnote because i own all the english mangas of that out. And not that anime with the short annoying but sart twat either. I just need something that stimulates those brain cells.

Higurashi no Naku Koro ni : It's a horror based anime that makes you go "WTF?!" and questions you as to what will happen next.

The series contains 3 different story arcs (another brain teaser for ya that get hinted at in the end) which boggle the mind.

You will be in constant check, trying to figure out what would happen next.

edit:

animenfo.com link http://www.animenfo.com/animetitle,3458,invgnk,higurashi_no_na.html

okay thanks, i'll look it up.

Detectice Conan, or, Case Closed (same show). There are some mysteries that will confuse the bloody hell out of you. And though it sounds boring, it was a very compelling show.

If not, then try Paranoia Agent. It's a psychological thriller, and the ending is one hell of a twist.

20th Century Boy, Ergo Proxy (sorta philosophical-existence thinky), Liar Game (drama but w/e)