Higurashi -Memorable Characters, Sad at some points, disturbing, and Hanyuu :3
TTGL -A little cliche at times but manly, giant robots, and a well endowed chick with a big ass...... [size=10]gun[/h] :D. What more could a man want?
Elfen Lied- Its very rare that I come across an ecchi that is not that comedic. I love how adorable the Dicloniuses are but at the same time lethal. Easily the saddest anime I've come across.
Chobits- Chii is just so adorable and the story is great
Azumanga Daioh- Memorable Characters and Surreal Humor is cool.
Kodomo no Jikan- I just hate the fact that people put it down because its a lolicon. Good Story, Characters, you'll laugh, and you'll cry.
High School of the Dead- Just all around kickass. Kohta Hirano roxxors