Lee Min Ho
Park Shin Hye
Lee Jong Suk
Suzy
Song Hye-kyo
Song Joong-ki
Jang Geun Suk 
Park Shin Hye  
Suzy  
Lee Min Ho

I don't really hate them but...I tend to avoid their dramas.
Park Seo Joon (I just can't with this guy, I saw him in She was Pretty and Hwarang and I didn't like him. Still...I really want to give him another chance 'cause maybe those roles weren't good). I will watch Fight For My Way soon, I hope I like him there.
I would say more but my english sucks..
Park Shin Hye
Gu Hye Seon!!!!!!!
Jang Hyuk
Kim Hyun Joong!!!!!!!!
Lee Dong Gun!!!!!!!!!!!!!!!!!
Kim Nam Gil
Kim Hyun Joong (lol he is so cringy in Playful Kiss) 
Kim Sae Ron (I don't know why I hate her hahaha)
Park Yoo Chun (I'm a fan of him before, but after the scandal.. I hated him)
SO JI SUB!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Sung HoonJang Hyuk.

I can´t help it, but I find them both really annoying. I´m watching two of their dramas right now and I´m stuck. I want to continue because I like the plot, but everything about them annoys me so much. Especially Jang Hyuks laugh..... They´re both popular, and I´ve seen them in more than one drama so it wasn´t just one role I didn´t like. I tried watching Fated To Love You because the plot sounded good and I´ve heard a lot about it, but when I tried watching it I just couldn´t handle Jang Hyuk and had to give up. Maybe I´ll change my mind in the future, but for now I try to avoid him as much as possible.
I can watch Sung Hoon´s dramas, he´s okay - but I´d rather not.
Fans of these guys, please don´t kill me it´s just my opinion which might change in the future (although that´s very unlikely - at least where Jang Hyuk is concerned).
actresses: Hwang Jang Eum (stop shouting woman) Park Shin Hye (do anything)
actors: Lee Seung Gi ( I tend to avoid dramas he's in) but I can watch the drama normally if it's good (same with the above actresses.)
Park Yoochun: I don't hate him, but his existence never tempted me to finish a drama of his.
for some reason, Lee min ho started to annoy me after City Hunter.
i'm here waiting for people to hate song hye kyo after there's news of her getting married with everyone's fav oppa song joong ki lol i love them
@Eliza I haven't seen Hwarang but Park Seo Joon was annoying in She Was Pretty but he's great in Fight My Way. I think it depends on the characters. 
I actually dont enjoy park bo young's performances