As for me there was only one winner.
1. How To Buy A Friend (2020)
Maybe because it was only 4 episodes long, so it's a bit unfair to compare it with full 16 eps where everything can happen regardless of whether it should happen.
The first scene in this drama takes place later in the plot, so we can wonder what happened to turn a very shy and timid student into a bloodied victim of the politician.
Honorable mentions:
Circle - Two Worlds Connected (2017)
I have FINALLY finished it this year. One of the best series touching upon family, humanity, AI, robots and brotherly love.
Designated Survivor: 60 Days (2019)
It was tight, nicely done, with heart(break) and some action.
