Heavy Dramas

I've watched many light-hearted dramas recently and now I'm in the mood for some heavy stuff. It could be either a crime/mystery drama or a tragic/psychological one.

Some examples: Signal, Tunnel, Gap Dong, Boku no Ita Jikan, etc.

Remember: War of the Son
Cruel City
Duel
Secret (2013)
Lookout/The Guardians
Liar Game (both Japanese and Korean versions are great)
City Hunter
Criminal Minds (Korean version)
The K2

If you want something similar to Boku no Ita Jikan you should watch 1 Litre no Namida (2005). It's probably one of the most popular tragedy dramas, and for good reason. 

cruel city 
missing noir
queen of ambition (very recommended)
the winter the wind blows
it's okay that's love
secret 
beautiful life (Japanese)
49 days
love me if you dare (Chinese)
lee jun kai (Chinese)
five fingers
golden rainbow
the devil
shark
last friends (Japanese)

Second Love Me if You Dare. It's a really great one, too.

You're All Surrounded was way heavier than I anticipated. It's also a crime/psychological drama.
If you are interested in a heavy movie then I would recommend Always. It's a type of a production that makes you feel all sorts of things.

Thanks for the recommendations!! :) I've already seen some of them, but I will definitely check the rest of them out!

(I didn't expect so many, so I guess I will bookmark the page and come back to it whenever I'm in the mood for heavy dramas)

White Christmas
Secret
Cruel City
LIFE
Save Me
Ningen Shikkaku
Last Friends
Zeni Geba
49 Days
Boku no Yabai Tsuma
Lipstick
God's Gift - 14 Days
Kamisama Mou Sukoshi Dake
Liar Game
N no Tame ni
The Quiz Show 1/2
The Village: Achiara's Secret
Yume no California

Movies:
Bleak Night
Pluto
Helter Skelter

guys i'm bookmarking this as well .. i'm really proud that most of the comment-ers are my chingus