Recommendations

They have very different plots but both have unique plot-twisters that will keep you on the edge of your seat and deal with dark themes/suspense/thrill. Horizon Tower has more mystery while Bad Kids has a unreliable narrator that requires the viewers to read-between-the-scenes to find the real truth.

They are similar because both FL know how to fight. Also, from one of Yang Mi's posters, she's in a similar position to Zhao Liying because she is also holding a bow and arrow in shooting position.

Both are zombie movies, both have two leads fighting to stay alive together, both are emotionally moving. Both are set in a closed environment, Alive is set in an apartment building while Train to Busan in a train.

They have the same writers. They main character is also a twin in both dramas. There is a prophecy about the twin characters in the drama that is important to the plot. They also both have complex characters, meaning likeable villains, protagonists with a dark side, and characters which we won't understand at first if they're good or evil

Both are music dramas. Beethoven Virus was my first Korean drama, which display perfect Music Industry, love, friendship and struggles between 3 leads in an orchestra. DYLB also gives me similar vibes.

-bickering couple
-arranged marriage
-great chemistry between leads
Both shows give off a similar vibe where the stakes aren't too high but the romance is strong!

The similarities are
rich famous male lead
Hate to love relationship
Tsundere personality of male lead
A Scene where leads are lost in a snowy place

It's the side story from The Lost Tomb like Reunion. The timeline is 2 years before reunion. It's more focus on the nine families and ofc, we still can see Wu Xie.

These 2 chinese rom-com has fake marriages between tough and martial arts trained princes ML and funny, smart witty FL.

These shows are kinda similar because in the happiest moments of their life they thought that was going to be their "happy ever after" but as years go by they get divorced. And then unexpectedly go to their youth.

The show invited seven girl group members to create their very own Korean drama series by becoming accredited scriptwriters as well as acting in the series as fictional versions of themselves. And able to perform on music shows as well.

same concept, added a few new cast like GOT7 JACKSON, KARA YOUNGJI.
this show is to make new relationship with others celebrities of making new friends, getting know each other.

Older male lead becomes young
Tries to develop a relationship with his son (and his daughter in 18 Again)
The difference is that the romance is between his wife in 18 Again whilst Mr Back is with an employee at his company

They both have college romance and very less negative roles. If you liked accidentally in love then you will like Love O2O for sure.

Both female leads undergo plastic surgery and a major appearance change. Diamond lover is more workplace/adult drama. As where Gangnam beauty is more college drama relating to image and status.