Both have a bar with interesting concepts regarding services and have interesting guests each episode.

Both are thrillers with supernatural/fantasy elements with some touching and sometimes sad stories.

Both titles are kdramas with investigation/thriller/crime element with a fantasy twist. They have similar vibe and touching moments.

Both kdramas are mystery/thriller/detective type with a fantasy element to them.
While Tunnel moves between different times, Missing moves between two worlds.

Both dramas revolve around office romance: Where stars land is set in an airport, while She would never know in a cosmetics company.
They both have slow growing romance and similar feeling.

Both are crime / thriller dramas involved in tracking serial killers, have plenty of twists and turns.
Both have cops/investigators that are involved more or less personally with their cases.

Both dramas involve retaired professional athletes and promote physical activities for non-professionals.
If you wish for nice motivational dramas to start doing sports these two are a must.

Both dramas have an excentric forensic detective/examiner as the male lead.
The VG deals with only one case, while PfJ has multiple ones

Both are crime dramas where the lead detectives and their colleagues try to solve an older case whilist going against their superiors.
Tunnel has a fantasy and time travel element, while The Good Detective has a more realistic setting

They both show the internal politics and struggles in a workplace: for Black dog is a school, in Hot Stove league is a baseball team. They both show faults of the systems they sorraund them. Both have no romance, but have a good portion of comedy and sometimes tension.

Both Memorist and Tell me what you saw revolve around crime investigation.
Also both have one of the leads with a special ability and one is a profiler.
In Memorist the ML has psychic powers and he is helped by a FL profiler, in TMWYS the FL has a photographic memory and she is helped by ML profile.

Both have one of the leads wanting revenge because of a tragic event of a relative in the past.
In Doctors is the FL, in Itaewon Class is the ML