I recently finished "1000 days promise" and i was positively surprised how different it was than all other kdramas i have seen, i always thought that every kdrama comes with childish/weak heroines, ridiculous & psychotic characters , singing teens,love triangles, unrealistic story lines( all the action dramas), cheesy love scenes , akward hugs etc etc (dont get me wrong i enjoy some of it, even though i have to admit thats not something to brag about ) but as it turns out i was wrong because "1000 days promise" had none of those things in it , i was wondering if there are any other korean dramas like that
I just added "1000 Day promise". I also like realistic dramas. I haven't seen many Kdramas so I don't know if there are any realistic ones around but I found Reply 1997 to be quite realistic but I haven't nothing to compare it to so it's just a personal opinion :)
Have you heard of the drama The Chaser? It's a revenge drama and I admit that the way the plot develops would probably not work like this in real life. But I think the setting of the story and most of all the characters, their emotions and the way they acted was very realistic. I got very emotionally invested in this drama because it showed real people imo and not the typical cliched characters. If you're interested in a crime solving drama you could also try Special Affairs Team Ten I also watched (and liked) the drama Can we get married? that witlily mentioned because it is a pretty realistic portrayal of couples, but be prepared for annoying parents that are interfering with their children's marriage a lot^^
The World That They Live In, with Hyun Bin and Song Hye Kyo
Little Mom Scandal is pretty realistic too.
I find Sign realistic. The way the plot goes works as what should happen IRL, atleast in my opinion.

Oh ya, its a medical(forensic doctors ; autopsies).
Can You Hear My Heart
Can We Get Married?
The Womand Who Still Wants to Marry
Beloved
Shut Up Flower Boy Band - Even thought is about teens and having a band, the drama isn't cliché and It feels like a real story.
It's Okay Daddys Girl