You know those moments that are so surprising that you just scream at your screen and need to watch the next episode. 

What Korean dramas have the most shocking plot twists/plot turns ever?

Of course you can answer with spoilers, so if you don't want to be spoiled be careful.

what happened in bali had a pretty crazy ending

The k-drama Black has a lot of plot twist, and many of them are very shocking:

for example, one of the plot twist of the drama that made me very shock is when we know that Ha Ram shot Joon with a gun when she was young by accident' trying to save his dad

K2 has a few plot twists

Chicago Typewriter

Circle

What happened in Bali - awesome ending scene

Hundred million Stars in the Sky - its a japanese drama but will soon be remade into a korean one

W - I remember being pretty shocked in almost every episode...well, but that's me!

To date Shut Up Flower Boy Band had one of the most shocking beginnings to a drama imho. There are several shows that have had great twists over the years until it was over used and became a cliche. One of the benefits of being a long time drama fan is seeing fresh concepts as they emerged and the joy of rage, sorrow or heart flutter watching it unfold. 

definitely cruel city has the most shocking plot twists eveeeer

cruel city... I remember it again.....dang...

That Winter the wind blows (that ending thouuuuu) 

Basketball (same there, the plottwist at the end....not in a good way though (in my opinion)) 

Save me and Bad Guys have shocking plot twists. 

Not korean but you must give it a try. It’s chinese, revolving about crime and psychology. Evil Minds would actually f* you up. 

 Czakhareina:

What happened in Bali - awesome ending scene

Hundred million Stars in the Sky - its a japanese drama but will soon be remade into a korean one

oh my god 1 million stars was THE DRAMA that got me hooked forever. nothing has had quite the same effect on me since. i was appalled at myself for not seeing it coming haha.  i probably wont watch the remake but its definitely worthy of one!