A drama where the lead female is not pretty. I don't mean where the lead male constantly tells her she looks like the bottom of a flower pot, but we ALL KNOW that the girl is drop dead gorgeous. I'm talking Ugly Betty syndrome. But, where the guy still falls for her being all studly and all. It doesn't matter if it's Korean, Japanese, Taiwanese, or Chinese. Just something good with romance!!!!!
Well... Miss No Good is pretty much this. Though it's the wig and tacky style of the character since Rainie Yang is gorgeous XD

I want to know more dramas like this ^^
My name is Kim Sam Soon...we all know she is beautiful.. but she tried to make herself less attractive for the role by gaining weight The Greatest Love It Started With a Kiss
Miss No Good looks quite interesting.
Well, these drama might fits on your category:

Mary stayed out all night
Scent of a woman
Which star are you from
Yamato nadeshiko shichi henge


Those girls starts in their minimal looks but eventually discover how stunningly beautiful they are later on.
Yamato Nadeshiki Shinchi Henge- The girl isn't ugly but the guy calls her Busunako which means uglySunako. Sunako isn't confident in her looks, she mostly covers her face and she likes horror and dark stuff. She starts living with these four guys that try to turn her into a "lady" of course one of them falls for her.. Another drama that is supposed to show that personality matters more than looks is Rebound, it starts off as Nobuko(main character) looses a lot of weight and she gets her dream job but then meeting this guy makes her fat again and you get to see how their relationship ends up after her change..The last drama that I can think of is It Started with a Kiss, the girl is adorable but everyone calls her ugly and she has this huge crush on this hot and smart guy in her school and then they end up living together...Don't make any assumptions according to my explanations I'm just not good at explaining dramas :)
It Started with a Kiss was like that. The guy always acted like he was looking down on her when in reality he was falling for her. And Ariel Lin is one of the prettiest Asian drama actresses. :P
I just finished Kimi Ni Todoke, and she's definitely not the most attractive girl in the world, (and she's not meant to be), it's based off an anime and the girl is supposed to be really creepy looking like Sadako from the movie The Ring, it was really quite cute because the guy still falls for her despite that and all the rumors going around about her.