Both are short and simple webseries about two boys rooming with each other.
Boys Dormitory focuses more on one character than the other while Roommate focuses on both.

These two both feature a group of people fighting some sort of crime.
Both of the casts have amazing chemistry and are equally funny! Both of these dramas have the same chaotic energy and I love it.

Both of these dramas take place in a farm setting. In both dramas, the FL is forced to live with the ML's family because of family issues.
They both have reasonable FL's and hot-headed yet kind ML's. The two dramas also have arranged engagements.
They're both super sweet and fun watches!

Both of these dramas focus on the lives of people involved in selling others or themselves in the sex trade and how they are slowly destroyed by the brutality of the business.

Both of these dramas have "ghosts" in them.
While He She It is more vengeful than cute, they both share the plot of a ghost staying on the earth because of their death.
Both of these take place at a university, and a particular song (or songs) is important to both of their plots.

Both of these thai school BLs have a sort of "horror"/"supernatural" aspect to their stories. They both try to tell the important message of accepting those in the LGBTQ community.

Both dramas are about insurance fruad and con artists.
While Mad Dog gives the characters good morals and makes them "heroes"/"robin hood" characters, Private Lives gives the character more shady morals. They're more of "antiheroes" than actual good people.
Mad Dog is an exciting drama with action scenes while Private Lives is a drama where everything slowly ties together and poeple fall into traps that have been ever so carefully laid for them.
The chemistry in both is very strong.

Ignoring the fact that their names are also very similar, these two both one supernatural lead and a regular human lead for the other.
They both have reincarnation plots as well as villains who were present in their past lives.
In both of these dramas, the main lead is very confident in his abilities.
Tale of the Nine-Tailed is about a nine-tailed fox looking for his reincarnated lover and meeting a paranormal show PD.
Legend of the Blue Seas is about a mermaid who meets her lover from her past life who is a con artist in his current life.

The ML's are both cold and arrogant.
The FL's are both kind of clumsy and very foolish.
Either one or the other of the MC's is rich as frick.
Both of these also have an sML!

Both dramas are about people who are all connected in mysterious ways and can see the missing dead.
In both dramas, one of the characters is a detective.

The story of a mother who would do anything for her child. Both of these moms meet their children after around a decade of separation.

The same leads are the MC's of both these dramas.
If you liked the childhood friend aspect of either these dramas, check out the other one!