Great Teachers ^^

A modern classic. Koro-sensei, with the appearance of a yellow octopus and a bunch of abilities, acts a techer at a junior high school where he teaches the worst class in the whole school. The thing is that he claims he'll destroy the moon and his students start the journey to kill him.

Ansatsu Kyoushitsu is a really fun story, the students keep growing with the guidance of koro-sensei and the fantasy-like elements are also really interesting

Onizuka is a former biker gang leader who is trying to become a teacher! The only thins standing in his way are the school and his class full of deliquents (boderline criminals)

This is ecchi so not for everyone, but if you don't mind it or if you can move on past that, then it's an amazingly funny story and Onizuka's journey as a teacher while he "guides" his students is worth reading

Solo-sensei is an skilled sorcerer and assassin tasked with the mission to assassinate a group of students at a fantasy school who will become evil mages in the future, according to Clairvoyance. However, he soon discovers that he may be able to change their future.

The manga doesn't have a lot of chapters yet, but so far the plot is interesting and the art is beautiful, including the designs.