Secret with Hwang Jung Eum and Ji Sung was a hardcore melodrama
Cruel City made me cry because the world is cruel. I recommend this one and 49 Days.
Currently on ep 15 on marriage contract and super sad, 
itt is sad but they try so hard to fight it and be happy that somehow makes it more emotional and sad
even while watching the happy scenes there is a tiny part of me that feels sad
Shinning Inheritance- made me bawl like a baby in the beginning especially when she was thinking about jumping off the building with her brother.
i avoid sad dramas like the plague, twice however I've started watching something before realizing it had a sad ending and that was i'm sorry i love you and the snow queen. 
Movies - The Classic, Barbie, A Moment to Remember

Dramas - The King's Daughter, Scarlet Heart (the Chinese original version), Empress Ki

Enjoy the waterworks! :)
  1. Flowers for Algernon
  2. Stars Falling From the Sky
  3. Good Doctor
the start was happy but as the episode goes by it starts to get sad
- The Way We Were
- Fifteen Years to Wait for Migratory Birds
- Autumn's Concerto

One of my first Korean movies was "Maundy Thursday" That was incredibly sad. One of these days I am going to revisit that movie to see if it has the same impact. "A Moment to remember" was another phenominal movie. For drama series I like "Chuno", "Autumns Tale" and  "That Winter the Wind Blows". Its funny after I watched "Queen Inhuyons Man" I just gave up on the rom-com genre. Nothing came close to QIM. Been wallowing in melodramas ever since.
Movies:
Maundy Thursday
A Moment to Remember
Werewolf Boy
Air Doll
Be With You
Boku no Hatsukoi wo Kimi ni Sasagu
I'm a Cyborg, But That's OK (this is not quite set as sad, it's about a girl, who thinks she is a Cyborg.... but I was crying through it all the time... call me crazy)
Koizora (the movie)
Matataki
Miracle in Cell No. 7
Tada, Kimi Wo Aishiteru

Specials:
When I Was The Prettiest

Dramas:
One  Litre of Tears
Koizora 
Last Friends
Padam Padam
Sunao ni Narenakute
Gu Family Book (Not because of the leads story, but because of the parents. It just so heartbreaking)
49 Days
The Classic, A Moment to Remember (movie)
Fated to love You
Master's Sun