Looking for really dark anime?

http://myanimelist.net/anime/8460/Mirai_Nikki

http://myanimelist.net/anime/152/Solty_Rei

(if you are into the robot stuff you'll lke this..sad ending too)

http://myanimelist.net/anime/9989/Ano_Hi_Mita_Hana...

http://myanimelist.net/anime/2167/Clannad

http://myanimelist.net/anime/1535/Death_Note

http://myanimelist.net/anime/1575/Code_Geass:_Hang...

http://myanimelist.net/anime/6547/Angel_Beats!

I will recommend:

Fate Zero(2011-2012) I thought this anime was really good( the animation, and story is amazing.) So good I would say download or torrent or watch it on crunchyroll. This show had many dark moments and I would say the ending is rather dark.

Also the Kara no Kyoukai Movies

Its a chain of 7 movies and they are not in the correct order you just watch them all and piece it together. For the most part all the movies are dark but still really good. These movies also have superb animation and the best way to go would to be to download a torrent.

Both of these were really good and dark with top notch animation. Even more supporting evidence is the fact that,

Fate Zero Blu-Ray(24 episodes)- $700

Kara no Kyoukai Blu-Ray(7 movies)- $1000

With prices like these that just tells you the animation is bad ***!

Madoka Magica does kinda have a...happier more open end ( except for Homura) in the third movie

Ummm Code Geass is similar...that one is awesome

Angel Beats is good

And Death Note

Black Butler ( which I'm yet to finish) is supposed to

RomeoxJuliet has a...more bitter sweet ending...but it ends that way because of the play

Elfen Lied

Berserk

Berserk, Death Note, Code Geass, Evangelion, Paradise Kiss (maybe, it depend on your concept of happy ending, this anime is sad for me D: )...

Well, I thought Bokurano didn't really have a "happy" ending. I'm not going to spoil it for you but there is A LOT of sad deaths in it, and the ending's sad too.

You might enjoy Code Geass! :)