Zan Sayonara Zetsubou Sensei [TV]

Nozomu Itoshiki is still the bizarre teacher of the even stranger Class 2-H. He attempts to teach his students the negative aspects of the world and society, only to have each circumstance thrown at his face whenever he tries. With more students and friends than before, Zetsubo-sensei’s life becomes harder and crazier than ever before.
(Source: ANN)

Similar in these categories.

The Melancholy of Haruhi Suzumiya

Ouran High School Host Club

One Piece

Chobits

Clannad

Soul Eater

Toradora!

Girl's High