Shahbaz BB7 is perhaps the most blatant example, pure childish behaviour from the likes of Sezer, Richard, Lisa, etc.
Both Sams in 6 and 7 were too, 6 seemed to be hated by absolutely everyone (including the public) and aside from being a bit ditzy and snooty in her Diary Rooms, it was a little confusing as to why she was so hated. I didn't even consider the transphobic overtones (I was going to say undertones but they were almost certainly overt) behind 7 at the time, but I think if we went over it with a fine-toothed comb now Grace and Nikki would be absolutely nowhere near as loved (and indeed shouldn't be
overrated caricatures)
No others spring to mind, I think instances with Deana/Isabelle etc were mostly the case of them standing up to vile people, I don't necessarily agree either were bullied.