My hit list would be:
Yoo He Yi (You`re Beautiful)
Oh In Young (K-POP The Ultimate Audition) - though the way she says "Ī`m Oh In Young! Superstar Oh In Young!" to me seemed a bit funny. But she`s still annoying.
Hong Se Na (Rooftop Prince) - she was just pure evil.
Go Eun Chan (Coffe Prince) - of course, I don`t hate her, but she kept being a girl a secret for sooo long I thougt she would deserve a slap to wake her up