Animation
Not too bad, the opening #1 is especially impressively animated. The graphical quality of the actual episodes varies quite much, though. It's almost like they hired different animators for some episodes. The lips/voice synq wasn't that great either.
Character design and facial expressions were great, though. Onizuka's face in hilarious!
I'm no hardcore ecchi fan, but I think there could have been a lot more of that in this anime. Since Onizuka is such a perverted guy, I think it would fit the theme well with more boobs and panty shots. =)
Sound
The opening and ending themes are ok. I especially liked the ending theme #2. Too bad it didn't last for more than a few episodes. Opening teme #1 is good, but I have a problem liking male japanese singers. Can't explain why.
I had no problems with the voice acting. Onizuka sounds a bit too old from time to time, but that wasn't that much of a problem. It fits him somehow. All the other voice actors were good too, as far as I'm concerned.
Story
Basically, most episodes are about Onizuka converting a student that previously was hostile towards him. Still, there are much variation betwen the episodes, and many great laughs to be had. Despite a few meaningless filler episodes, most drives the story forward.
I didn't get the ending at all though. Is that what you call an ending (happy or not)? I think this anime deserved one.
The abrupt ending also leaves lots of loose ends. The manga was more slow-paced, so I hope more will be explained there.
Character
Yay, lots and lots of interesting characters! Since this is a rather long anime, most of them get at least decently presented. I think it could have been even better, though. In 43 episodes, there could have been much more character development. There actually are quite a lot already, but I wasn't entirelly satisfied.
All in all, I loved most of the characters. The main reason I didn't give GTO a 10 here, is in fact Onizuka himself. He gets too much screen time, and always interferes when other characters are starting to develop. He flies in like a superhero in the end of every episode, and the other characters never get to solve their problems on their own. I still like him, it's just that he gets in the way of everyone else.
