bolded what I enjoyed the most out of these:
definitely park chan wook's "vengeance trilogy": sympathy for mr. vengeance, sympathy for lady vengeance, & old boy.
+1 for memories of murder & train to busan
you might also want to check out a tale of two sisters, mother (2009 bong joon ho film), & some adaptations based on kanae minato's work that are supposed to be very good. I have seen/started these: confessions (2010 movie), n no tame ni, & yakou kanransha. there's also shokuzai & the snow white murder case that may be worth looking at. you might also like the good, the bad, the weird (quirky action/adventure comedy about a bounty hunter & two very different outlaws).
+1 for the man from nowhere. I feel it's overrated but I still enjoyed it. I don't personally rec I saw the devil but it might by up your alley.
dramas: +1 for cruel city, +1 for bad guys, missing noir m, border, seirei no moribito (fantasy/action/adventure), boku no yabai tsuma, ishi no mayu, suisho no kodo, white christmas (2011 kdrama), suna no tou (gets interesting/more suspenseful around eps 4 or 5), & cold case: shinjitsu no tobira (the jdrama version of the american cold case).
