^ second that.

Oh My Ghostess. The Lover.

tvN got so many good kisses drama~~~~
Shut Up: Flower Boy Band
High School King of Savvy (even if i have mixed feelings about the ending)
Cheese in the Trap
Reply series
Oh My Ghostess was also pretty good, very cute too :3 
Not really fond of tvn, I always had low expectation the only drama that exceed : marriage not dating, cheese in the trap (love it)
Misaeng (my favorite drama of all time)
Signal (my favorite currently airing drama)
Let's Eat 2
Reply 1994
Reply 1988
Marriage, Not Dating
Oh My Ghostess
Oh My Ghost 
Signal
Reply 1988 

Signal
Reply 1997
King of High School Life Conduct
Liar Game
Marriage Not Dating
Ex-Girlfriend Club
Emergency Couple
Gap Dong
Marriage, Not Dating  --- It was so good, I wish they will make #2 :) 
Oh My Ghostess! is the best.. tvN really chooses their dramas so well.. I've been watching lots of their drama series lately. Hope for more equally good series.
- Signal (duh)
- Hidden Identity
- Nine: Nine Time Travels
- Dear My Friends (airing!)
Bubblegum 
Let's eat 
Oh My Ghost
Valid Love 
Signal
Nine: Nine Time Travel
Misaeng
Let's Eat Season 1
Signal is the best...but I love all tvN dramas
Oh Hae Young Again
Nine: Nine Time Travel
The Reply Series
Oh my Ghostess
QUEEN IN HYUN'S MAN 
Its so amazing I watched it like 5 times.
Dear My Friend (not only the best of TVN but perhaps the best life drama ever)