Sun, played by Yunjin Kim.
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I know, I know. More traditionalists would answer Ben or Locke or Juliet, but not me. This week's season finale solidified in my mind that the character of Sun is the most interesting and most dynamic character on the show. It doesn't hurt that Yunjin Kim is a fantastic actress either.
Just look at where she started in comparison to where she is now. In the first season, she was the largely silent and dominated wife of Daniel Dae Kim's Jin. She was meek and afraid to speak to others. Soon, through flashback, we learned that we didn't have the whole story. We learned that she spoke English, that she had been planning to leave her husband, that she had an affair. Eventually, Jin found it, and they've become equal partners in the relationship. Where the last part of Thursday's finale leaves them is open for debate, I think . . . I'm not totally buying his demise.
And now, in flash forwards, it seems that Sun has become the same kind of shrewd yet cruelly calculating business woman as her father. Did she approach Charles Widmore to get back at Ben, or is she setting a trap for the shady fellow and father of Penelope? I have no idea, but I'm interested to see how much further they can develop this constantly growing character.