Korean Thrillers to Die For (Pun.....intended?)

I have been a huge fan of thrillers for as long as I can remember. Then kdramas happened in my life and ofcourse I found my way to the thrillers pretty soon. So, I thought why not share it with like-minded people. Also, no, I am not critical while rating movies and shows. Something keeps me hooked, something makes me feel a lot, something has outstanding cinematography, direction and acting - I give it a 10. Some might not have any rating - this might be because the show amazed me in some ways and frustrated in others, both extremes (cough*Penthouse*cough). There's little to no romance in most of these except Flower of Evil and Devil Judge (if you know, you know). I'll keep adding to this list as and when I watch more :)