Sayonara Zetsubou Sensei OVA.
Goodbye Mr. Despair OAD is finished and has 3 Episodes. It is also Known as: 獄・さよなら絶望先生, Sayonara Zetsubou Sensei OAD, Goodbye Mr. Despair OVA, GSZS
Genres: Earth, Japan, Asia, Comedy, High School, School Life, Present, Parody
2. Gintama

The Amanto, aliens from outer space, have invaded Earth and taken over feudal Japan. As a result, a prohibition on swords has been established, and the samurai of Japan are treated with disregard as a consequence.
However one man, Gintoki Sakata, still possesses the heart of the samurai, although from his love of sweets and work as a yorozuya, one might not expect it. Accompanying him in his jack-of-all-trades line of work are Shinpachi Shimura, a boy with glasses and a strong heart, Kagura with her umbrella and seemingly bottomless stomach, as well as Sadaharu, their oversized pet dog. Of course, these odd jobs are not always simple, as they frequently have run-ins with the police, ragtag rebels, and assassins, oftentimes leading to humorous but unfortunate consequences.
Who said life as an errand boy was easy?
Gintama is finished and has 201 Episodes. It is also Known as: 銀魂, Gin Tama, Silver Soul, Yorinuki Gintama-san
1. Nichijou

Nichijou primarily focuses on the daily antics of a trio of childhood friends—high school girls Mio Naganohara, Yuuko Aioi and Mai Minakami—whose stories soon intertwine with the young genius Hakase Shinonome, her robot caretaker Nano, and their talking cat Sakamoto. With every passing day, the lives of these six, as well as of the many people around them, experience both the calms of normal life and the insanity of the absurd. Walking to school, being bitten by a talking crow, spending time with friends, and watching the principal suplex a deer: they are all in a day's work in the extraordinary everyday lives of those in Nichijou.
Nichijou - My Ordinary Life is finished and has 26 Episodes. It is also Known as: 日常, Everyday