You're Beautiful is definitely in my top 10 favorite dramas, and may even make the top 5 list.
What's It About?: An almost-nun anmed Go Mi Nyu pretends to be her twin brother (Go Mi Nam) when he has a botched eye job and has to leave for America. At first she's reluctant to participate, but does it to find her mother.
I absolutely loved this
There are attractive males left and right, and the story isn't dark and depressing. It's not constantly humor, but it's not lacking humor either. (Not to mention Jang Geun Suk and Lee Hongki! *fangirl squeal*)
This, Secret Garden, and City Hunter are the dramas I use to pull people into the world of Asian Dramas, and it works every time. Unless you hate humor, you shouldn't be disappointed.