Cromartie is an aburdist, short-form comedy (roughly 10min episodes) which parodies of the Japanese 'Juvenile Delinquent' genre, that was extremely popular in Japan, in the 80s and 90s- in anime and manga, as well as live-action TV and gloriously cheesy, cheap b-movies.
If you ARE a fan of the JD genre (stuff like Sukeban Deko, Yu Yu Hakusho, Baki the Grappler, Initial D, GTO, or even Stardust Crusaders-era Jojo) you should enjoy this series, but you don't really have to know the genre, to appreciate the glorious, played-completely-straight absurdism of Cromartie.
It's hard to describe Cromartie; Other reviewers have mentioned britsh comedies like Monty Python, and although Cromartie has some huge differences, being a satire, set in High School for delinquent teenage boys, the overall style and quality IS comparable (which isn't a comparison I'd make lightly. Monty Python are some big shoes to fill). The Mighty Boosh and The Young Ones also have similar appeal.
It can be very hard to pull off this kind of absurdist comedy, without lapsing into forced, painful-to-watch, "lol so random" cringe. But Cromartie does it beautifully.
I've seen literally hundreds of anime series' (sad, I know), much of it goddam terrible, especially comedies, which can be hard to translate, across cultures- But Cromartie is in my all-time top 10, and has as much re-watch value as classsics like Cowboy Bebop, FLCL, or Evangelion.
Different people like different humour, but Cromartie is a solid 10/10, in my book (and I score shows pretty harshly)
Also, Cromartie has arguably THE greatest opening theme music, in all of anime... (well, on par with Bebop's... and Eva's.... and Space Battleship Yamato's... and Science Ninja Team Gatchaman...)
