Hwang Jung Eum- her face expressions, her voice (she should not really do narrations, it sounds like she's reading off from a script), and her inability to have romantic chemistry with her male leads. 

Park Shin Hye- I've seen her since stairway to heaven, thought she was good. But her popularity grew faster than her acting skill.

Lee Min Ho- I don't know, maybe it was because his popularity is so big yet I find nothing special about his acting.

Lee Jong Suk- He seem to act like himself, and I don't really like that. All his characters seemed like one person with the same attitude and mannerism. I find myself not wanting to see him in a drama that I'm anticipating for, but the roles seem to always go to him like Pinocchio, W,  Doctor Stranger, and While I was Sleeping. 

Yoo Ah In: good actor. It's just my opinion that when I see him in a role, I imagine someone else that could have matched the character. I think it's his face and build. 

others: Jang Geun Suk, Nam Goong Min, Yoon Eun Hye

A few more I just thought of are 
Kim Go-eun
Definetly Song Joong-ki
So Ji-sub
Gong Yoo
Lee Jong-suk
Song Hye-kyo-____-
and i dont think lee joon gi is overhyped at all because all his characters are really good and some are really exceptional if you ever saw his movie you would know why he gets so much praise. even if few of his dramas are badly scripted he never disappoints



i think they are over hyped not over rated
         lee min ho
         lee jong suk
         kim soo hyun - even though he is a very good actor some times his crying shots feel awkward and unnatural  imo
          park hae jin- i dont get it
         ok techyon   singer- yes actor -no
        song hye kyo
          han hyoo joo
          park shin hye acting in movies is really good than in dramas may be she always gets offered such roles
          baek hyun not that he was bad in fact the character he is supposed to play is chidish, ignorant little foolish and later on his character matures its the                                        same as how it was presented in chinese version but the praise he gets is a little too much i guess due to exo
          gong yoo-some times he seems really excellent and some time does not really connect to me
     
I used to think Lee Jong Suk was overhyped and overrated until I watched Pinocchio. He is such a good actor.
lee min ho 
park shin hye
song joong ki
song hye kyo 
jang geun suk
lee jong suk
kim woo bin 
kim soo hyun
jun ji hyun
IU (sry not a fan of IU at alllll... i do not dislike her anymore cuz shes close w/ si kyung oppa... ) 
but theyre all good at acting tho
I loved loved LOVED Lee Jong Suk in Pinocchio but recently, his roles seemed to bug me. I don't know if it's too much aegyo or what but there's something about it that irks me.

But I still love him though. Idk, oppas make me cray lol

Lee Kong Suk
Kim Woo Bin
Park Shin Hye

Park Hye Soo
Shin Se-Kyeong
Im Yoon Ah

All of above are over-rated.  The only 3 i "can't stand" watching though are the last 3. 


Lee Min Ho
I liked him in Personal Taste, but I was underwhelmed with Heirs ... I couldn't even finishe Boys before Flowers ... 
Actors:
- Lee Min Ho
- Song Joong Ki
- Lee Jong Suk
- Jang Geun Suk
- idol turned actors like Yook Sung Jae, their popularity growth are way lot faster than normal actors. K-pop fans just can't seem to find any flaws in them (except Do Kyung Soo, he's proven a good actor)

Actress:
- Suzy
- Yoona
- Song Hye Kyo
- Park Shin Hye
- IU
Lee Minho, Yoona and most idol actors/actresses
really park shin hye she looks sad all the time
Lee Min Ho
I always avoid his dramas now because he seems to always play a jerk in every one. I'm sick of it.
Lee min ho
Park shin hye
Hwang Jung Eum