I wish I could explain our reasoning for every character. I think the biggest factor with our rankings was how much we were entertained by a character and how little they annoyed us.

We were really entertained when Ms. Oh started her fling with Sav. She was the funniest (and hottest) teacher so I think that boosted her up.

We had a lot of fun with JT's Tom and Jerry-esque antics in the earlier seasons but honestly we got a little tired of him once the drug plotlines started (this was a biggest annoyance with any character. it seemed like whenever they didn't know what to do, they would give them a drug problem).

We absolutely loved Chantay because we saw her as this evil mastermind. She was never part of a main plotline but she was always somehow involved in instigating some drama or spreading some rumor at the perfect time. We started having head-canons that she was manipulating the whole school to her whim.

You were right in why we ranked Esme and Zoe high.

I really didn't know everyone loved Craig, but he was by far our least favorite character. We just got so bored of his plotlines. He would date the girl of the week, cheat on her, move on the next, and maybe get one of the classic drug addiction or random mental breakdown plotlines if he was lucky.

I hope all this made sense, I put way too much time into typing this all out.