Bad Guys – bad cop recruits team of bad guys he put in jail to put really bad guys out of circulation.
Black – multi-arced supernatural / crime mystery with romances and bad guys.
Argon – power of (positive) media vs. corruption.
A Man Called God – 007 in East Asian guise.
Common elements in these series include: high production values, humor, drama, romantic tension, views of another land and culture, Korean dialogue with English subtitles, and did I mention multiple arcs and twisty plots ..