City Hunter : Kdrama. Revenge story, more of a thriller than a suspense drama. There is romance in it.
Ghost : Kdrama. Police drama about a cyber police unit. Mystery but no romance. Despite the title, it's not about ghosts.
Guilty Akuma To Keiyakushita Onna : Jdrama. Crime story about multiple suicides. Romance also.
Healer : Kdrama. Thriller, action, mystery, romance... You'll like it.
H.I.T. : Kdrama. Police drama about a serial killer if I remember it right. Romance in it.
I remember you : Kdrama. Police drama about a serial killer. It's a good thriller with romance. If you liked Pinocchio, this should be your cup of tea.
Kurosagi : Jdrama. Revenge story about con artists.
Love Me If You Dare : Cdrama. Police drama. I'd say if you like I remember you, you should like this one too. Suspense, thriller, romance...
Signal : Kdrama. Number 2 (sometimes number 1) on MDL and my all-time favourite. A cop receive radio transmissions from 20 years in the past. Not much romance but still the BEST.
Spotlight : Kdrama. Crime drama involving journalists.
Who are you : Kdrama. Crime and ghosts story. Suspense, mystery and romance.
You're all surrounded : Kdrama. Police story, kind of like I Remember You as well.