Never heard of this show before but was able to find all the episodes and decided to watch them all. I am left surprised that it was really good given I had no idea what it was about.
Onizuka is an inspiration to his students and that kinda spills onto the viewer as well making you feel good about yourself inside. The things he goes out of his way for his students is a strong virtue not many people possess. Mix that with some comedy (mostly him being a idiot) and you have a decent show on your hands.
But, as a future teacher, I was interested to see his teaching style and can easily say if I did any or most those things, I would probably find myself living off government welfare for a long time. That's not to say it's not entertaining but dunking students into water upside down isn't exactly a good indication that you are concerned about a student's wellbeing (Also, allocating students to stay in rooms with the opposite sex is... looked down upon). Indeed, I share his feelings for drowning students as they can be a massive pain in the ass.
The perverted and often idiodic protagonist is a character unrelatable to anyone who has sane mind and that's why it's good for a bit of pure escapism. I was hoping there'd be more episodes but the ending is somewhat justified albeit open ended. Definately worth a look into.