Recommendations

This one is related to 2gether, it's the second part. I recommend watching it if you liked the first part.

Both have authors in manga/manhua stories coming alive in one way or another. W the main lead jumps into the manhua.

Similar in the sense that both male leads appear weak to everyone and go through hardships like bullying, but later becomes really strong and proves them all wrong (in the best most thrilling ways)!

the same story where the princess married a hero, not a king but I think both have a good concept. In rebirth for you the hero knows the heroin identity in the 2nd or3rd episodes but in The Flowers Are Blooming (2021) the hero comes to know heroin identity after some episodes.

Rampant is a 2018 South Korean period action zombie film directed by Kim Sung-hoon. The film features a clash between exiled prince Lee Chung (Hyun Bin) and the Joseon minister of War Kim Ja-joon (Jang Dong-gun) with the backdrop of a spreading zombie plague. (via Wikipedia)

This two movies has the same soft tone, even the music about the same.
Both female leads are so beautiful that you just can’t take your eyes away from the screen.
Also their voice is so gentle and magnet like
Both movies are very die hearted romantic,

Both are action packed and slow paced w/the development of the characters. Artsy and Intriguing, as well as the plot in where the two protagonist help each other solve a crime :DD

Both of them have main focus are Vampire.
Same actor (Kim Ji Woong) who play vampire role.
School/Campus setting.

Both tell about the palace story written by an author which later on the author turn to wake up as one of the character in the story that turned out very hilarious. TRoTaR is much better.

A drama with identical twins where one twin pretend to be the other while one is recovering from an accident. She also finds love along the way as she finds herself.

Both are about running LOL
Athleticism, sport, persistent, hard practice
Encouraging, competition, , inner struggle

Both are about the military and special forces teams as well as the friendships and love formed on the way.

Both stories are about a group of people trying to reveal hidden mysteries. Both have good chemistry main couple, it’s not romantic but the explosive chemistry is worth watching. Chimera does have a better background story than The Good Detective.

not so similar but both have interesting touch to Crown Prince Sohyeon (who was ahead of his time, wanted to bring modern things in Korea).
While he is ML in 3 Musketeers, In The King: Eternal Monarch. Crown Prince Sohyeon, in a parallel universe, lived on to become king. His reign would cause a chain reaction that culminated in a modern constitutional monarchy.

both drama ask question, what would be if Prince Sohyeon became King as he should be.

In both dramas FL is a reporter and ML a superstar. I think these two dramas are similar on that aspect