Queen of Ambition. You watch the first 5 minutes and you already know it will hit you right in the feels.
For me it`s Missing you I usually don`t watch sad dramas, but couldn`t help myself with this one
Dramas that turned me into an ugly, sobbing mess: The Princess' Man, 1 Litre of Tears, Meteor Garden, Tree of Heaven, The Snow Queen, The Moon Embracing the Sun, Missing You, Bridal Mask, Can You Hear My Heart, King2Hearts and probably more I can't remember
So far there have been a few, like parts of Fated to Love You, but definitely the ending of Bad Guy. The dramas that had me going from beginning to end were Scent of a Woman, and 49 Days.
for me the snow queen <3 , 1 litre of tears and bridal mask these dramas made me cry and usually i don't cry easily
For me~Missing you/I Miss you
"One litre of Tears" and "Tree of Heaven"... So sad ^^
Queen In Hyun's Man The Bridal Mask :(
A Love To Kill.....had me crying all the time.
Sad Love Song hands down. I watched that drama aboout seven years ago on TV before I became addicted to Asian drama, that's the only drama that made me cry and I say that because I am icy cold-hearted who never cries over dramas or anything else as NEVER.
1 litre of tears and Sorry I love you T^T
The saddest K-DRAMA but my favorite..... WHAT HAPPEN IN BALI ...I still cry just by listening only OST ....a real broken heart

There ara also : The Princess' Man, Tree of Heaven, The Snow Queen, Missing You, Bridal Mask, Can You Hear My Heart, Padam Padam,Damo...ect....

But although they are "sad dramas" ...these are my favorite dramas yet, because often the love story is great, the characters are bruised, wounded...making this unforgettable drama

ps : Sorry for my poor english