I started (and finished) the first series of this anime quite a while ago. Last year, in fact. It was one of the shows that my university anime club introduced me to, and I am so thankful to them for that. I recently marathoned the whole first series again, and I’m so glad I did.
Sayonara Zetsubou Sensei, also known as So Long, Mr. Despair to those who followed a.f.k.’s fansubs, is adapted from the manga with the same name, as it happens. The story was created by Koji Kumeta, who we get to see a lot of throughout the series, given that his head appears a smattering of times throughout each episode. It’s this kind of behaviour that makes SZS stand out for me as a great example of anime.