Ok. Here goes: Cromartie High school is a manga about badasses doing badass things. Really good manga. Lots of joges and hijinks going on. According to it's wiki page, The series is a parody of Japanese "yankii" (juvenile delinquent) manga of the 1970s and 1980s.
There were some really good chapters around, like the Mechazawa chapter or the one that references the Planet of the Apes movies. It has a really clever twist, but I don't really want to spoil it. Just go read the manga. I also really liked the one chapter were a "duo of badasses" from another town that kick the tar out of everyone in the local city. There were multiple chapters were I wasn't sure why they were cut from the anime.
But then there were chapters that really sucked, like the ones dedicated to those KISS band knockoffs or the sumo chapters. They were really boring. I could understand why it didn't show up in the anime at all. It was very entertaining to read all the way through. The manga artist, Eiji Nonaka , is currently working on a spinoff manga from the perspective of the adult teachers from the school. We'll see how that goes.