On that list, I can only really talk about Jackson because I tuned out of Gossip Girl a long time ago so I don't really pay attention to Chuck. As for Jackson on Teen Wolf, he was supposed to be a jerk, the I'm-better-than-you and I'll-do-anything-to-get-what-I-want type of guy. I actually loved him for that. And he got what he wanted, except it began really badly and I actually felt sorry for him and had hopes in season 3 until it was announced the actor wasn't coming back...

If they really wanna talk about bad characters, they should mention Cordelia Chase season 4 of Angel. The only episode of that season I love her is the memory loss one because she's back Sunnydale!Cordy.

Kennedy in BtVS, she was a bad character. Annoying and badly written I'd say.

Really thinking about it, there are two ways, at least, to describe bad characters... the badly written, interpreted ones and the annoying/bad/mean ones written that way...