I found my love for this once I watched Signal and Stranger. If any one would recommend me shows like that. that would be so pleased. I am watching Crash Landing on You and I find it funny and good but not as good as the first two shows I mentioned. It is still a good show. But pretty much I need shows like thriller crime detective aand along that road. 

Hey there, welcome!! 

I haven't watch Signal nor Stranger but maybe The Lies Within is pretty much the kind of kdrama you like. And there is also Tunnel (2017). Strangers from Hell isn't a crime or detective story but it's a well known thriller so you can give it a try. Those are the one I've watch at least some episodes so far so I can mention it. But you can search for thriller and crime drama lists in this site, you will be able to find many others!

Hello monster

Circle- like signal, different timelines

Tunnel is a great one, I second that opinion! It almost has a similar crime/time-travel elements that Signal does but focuses a bit more on characters and the emotions of everything. 

I’d also second the Circle recommendation, very tightly plotted mystery drama that has great twists and turns like Signal.

I’ve heard good things but haven’t personally watched Life On Mars and Mother. 

Lastly, this isn’t like Signal that much, but you might find City Hunter interesting. It’s a bit more action focused but is centered around a conspiracy and is a great story. 

Everything above and Voice 1, Voice 2 and Black.

Also, Tell me what you saw is currently airing and it’s pretty good. 

If you into Crime /Suspense/Action/Supernatural/Mystery/Thriller

  • Missing Noir M
  • Children of Nobody
  • Vagabond
  • Gap Dong
  • Remember: The War of the Son
  • Black
  • Healer
  • Cruel City
  • Defendant
  • Two Weeks
  • Memories of Murder
  • Bad Guys
  • Mad Dog
  • The Merciless
  • Liar Game
  • Lucifer
  • Player
  • Duel
  • Special Affairs Team TEN
  • Hello Monster
  • Leverage
  • The Fiery Priest
  • Forgotten
  • The Village : Achiara's Secret
  • Doctor Prisoner 
  • Confession
  • A Beautiful Mind
  • Life
  • Misty
  • Terius Behind Me
  • The Guardians
  • IRIS
  • The Man From Nowhere
  • Graceful Family
  • The Smile has left your Eyes
  • Watcher
  • Come and Hug Me
  • Kill Me, Heal Me
  • Confession of Murder
  • God's Gift: 14 Days
  • The Bridal Mask
  • Chicago Typewriter
  • The Guest
  • Different Dreams

I also second the dramas mentioned by previous users.