Recommendations

both are stories 'down to earth' - I mean, they're showing the reality, the real world and real life, and you still enjoy them!

Both drama, set in historical period, have a beautiful and interesting
plot based on the protagonist's revenge.
The female protagonists are both strong, smart and skillful.
Both drama have a lot of episodes but they are very exiting and never boring.
Princess Wei Young are better in costumes clothing and filming.

both are set in historical period.
both the male main character “Wang So” are cursed princes destined to become king.

both have a female main character who dresses as a man.
both are set in the world of idol music.

Both have an immortal fall in love with a human. There is conflict in knowing that they will never age so this sets the pacing when do come across that one person who intrigues and makes them 'fall' in love. LFATM is a short drama so easy to marathon, the characters are fun and likeable. Immortal leads in both, face inner conflicts in trying to make the right choices about love, and their own personal purpose of the life they live.

Both are mini-dramas with the same male leads. One is about a new love with some fantasy elements while the other one is exploring what happens after the love ends.

They are both historical drama with beautiful cast and settings and is both entertaining and hold deep meaning for Korea history!! Both have idol actors and the acting debut of two popular kpop stars- Kim taehyung(v) from BTS and Byung baekhyun from EXO!!!! You gotta wtch these amazing drama with amazing music!!

It's about an ex-couple meeting each other again some years later,

Girl travels back in time...and influences the past with her modern views..SSL is only two EPs but still it's worth it.

Same plot...girl time travels to past. An amazing drama with amazing cast

the main couple in both dramas are really cute and have great chemistry :)

It's the second movie of this one, so it's bound to be similar.

They are both supernatural. In Gumiho, the main girl is not a human and in order to become one she needs a human. She is +500 YO.
In Goblin, Kim Shin is not human too. He is +900 YO. He wants to end his immortality. In order to that he needs a human bride.
Goblin has more interesting storyline and has a strong sweet bromance too.

Both of these dramas are about high school students have have a cutesy feel as well as supportive friends. Both have shared actors - Sakurada Dori and Shiraishi Shunya!

both have a similar feel to it. Jenius focuses more on investigation and sci-fi while Simple Man crosses many genre from sci-fi to investigation, action, mystery, medical and paranormal. Personally, I prefer Simple Man over Jenius but both are really good dramas if you are into cleverly made quality mystery, investigation type dramas.