Top 9 in Top 10 best anime by studio Shaft ranked by IMDb.
Studio Shaft's anime trailer, Sayonara Zetsubou Sensei
Through four seasons and an original video animation of the anime Sayonara Zetsubou Sensei produced by studio Shaft, it introduces viewers to a bored teacher and his eccentric class. Possessing an IMDb 7.7 for all four seasons averaged, Sayonara Zetsubou Sensei ranks 9th on the list.
The main character is high school teacher Nozomu Itoshiki, who is extremely sensitive to negative events, every little thing pushes him into misery, even suicide. The original premise of Sayonara Zetsubou Sensei is used as a springboard for many satirical, humorous, and dark moments. For an anime that deals with such a bleak aspect of Japanese culture, it's a wonder how it manages to make some dark themes interesting.