Best Actresses based on acting ability

Although she didn't have a major role I loved Woo Hee Jin as Court Lady Oh in Moon Lovers. She had such a grace about her and as we got to know her character I couldn't help but appreciate her as an actress for having both a deep emotional side yet remaining so composed. ♡

Song Yi Kyu, Lee Yo Won and Ha Ji Won

Park Shin Hye- I know a lot of people won't agree with me, but I have always been really impressed with her, especially in Tree Of Heaven. She was only 16 at the time and I think she was wonderful.

Kim Sae Won- This girl is amazing! Even as a child actress, she was tackling serious roles and doing a better job than most adults. Acting just comes naturally to her.

Kim So Eun- She is just like the girl next door. Unlike a lot of other actresses, she always looks and acts so natural.

@Hanah

Kim Hee Sun is my favourite.  I really love her.  As you can tell from my profile pic, I love Kim Mi Kyung too.  and my third favourite is Kim Seul Gi.  They're my top 3 actors male or female :)  The thing that ties them all together is their comic timing as well as their versatility.

AND, new question for everyone. What do you think contributes more to a good drama--the actor or the script?
I was reading an article about the "Big 3" vs. the cable channels, and their approaches. Basically, it seems like the Big 3 use big-name actors/actresses to draw the crowd in, while cable channels are using better-written, fresher scripts. Of course, just because the lead actor/actresses is famous, doesn't mean he/she is better at acting than a newbie, but the article just got me wondering ;) 

hmmm..for me its Choi Ji Woo.. ) 

@Hanah and @eternalcities  For me the most important thing is the character and how they behave which directly points to writing.  I guess writing consistency really. I can deal with some plot holes but I can't deal with underdeveloped characters or characters who behave strangely.  Actors can enhance those characters and sometimes they can act them badly, but a really good character will live through that bad acting.  I'll give you an example.  I LOVED Signal.  absolutely loved it to bits.  but the lead actor had the same expression on his face the whole way through and it drove me nuts, but because his character, and the story were so well written they could withstand it, I still cared about him and what happened to him, I still loved the drama even though I thought the lead was wooden and weird.  

Then, there's the opposite, when excellent acting can't save ridiculous writing; my example is Missing You.  I quite like Yoo Seung Ho and Yoon Eun Hye, I have no doubt both of them are excellent actors but the writer and director just made them cry for the whole second half of the series.  Even though they're both really, really great at crying, I wanted to bang their heads together by the end of it and tell them to toughen up. Excellent acting could not save that drama for me.  The sad thing is the plot was great.  I just stopped caring about the characters because of the writing.