I think there's a similar thread here:
http://mydramalist.com/forum/showthread.php?4627-What-kind-of-drama-you-like-the-most
My answer was:
If I had to choose then it would be
korean dramas, but I love other dramas too, especially
chinese and
taiwanese. Right now I'm in a minor drama slump so I try to watch more chinese and taiwanese dramas to practice my chinese. I prefer taiwanese dramas that are well-made and not as dorky / cheesy / dramatic as they tend to be sometimes (even though I like them too). Same goes for
thai dramas, it's important that they're well-made and not too much. Nowadays there seem to be a lot of great thai lakorn out there, so I try not to watch as many of the old ones as before. They've often got too much violence, rape and drama. Not to talk about the weak plot lines. I mean, I don't mind kiss-slap dramas (I love them, hehe), but they've to be good and without rape. So yeah, I love thai lakorn as long as they're good, like Taddao Bussaya or Tawee Pope.
I also watch a lot of
japanese dramas, but I rarely find good ones. Most of the jdramas out there seem to be so-so compared to all the great korean dramas, haha! But when I do find a good japanese drama I totally fall in love with it.