beelzebub
oresama teacher
http://www.mangago.me/read-manga/gang_king/
http://www.mangago.me/read-manga/sugarless_hosokawa_masami/
http://www.mangago.me/read-manga/angel_densetsu/
http://www.mangago.me/read-manga/great_teacher_onizuka/ And the other GTO manga
http://www.mangago.me/read-manga/gokusen/
http://www.mangago.me/read-manga/kongou_banchou/
http://www.mangago.me/read-manga/a_bout/
http://www.mangago.me/read-manga/rookies/
http://www.mangago.me/read-manga/rokudenashi_blues/
http://www.mangago.me/read-manga/holyland/
http://www.mangago.me/read-manga/kyou_kara_ore_wa/
http://www.mangago.me/read-manga/ocha_nigosu/
http://www.mangago.me/read-manga/crows/
you mean this type of thing?
http://www.mangago.me/read-manga/gokusen/
also looking at tags is a good idea:
http://www.mangago.me/tag/delinquent/
I'm looking for Non-yaoi delinquent manga, any help is appreciated.