Recommendations

Figuring unique and interesting group of leads with strong personalities complementing each others. Each character was well built and funny, with their own problems and flaws. The story creates a world where they all became friends instead of narrowing it down to just the leads. No unnecessary love triangles. Talk about how they met each other and grow/heal together. The dialogue is witty and meaningful.

Both are crime dramas that debate the morals behind of ones personal justice. Both deal about characters that change due to things that have happened to them. Both are absolutely mind blowing in terms of character complexity, story development and cases. Absolutely unforgettable experience.

+ Both dramas are extremely well connected crime dramas where the cases are linked to the characters on a personal level.
+ both thematize the psychological aspect => While in Signal the psychological aspect is more debated and analyses, in Burning Ice you can really see psychological methods being used.
+ Both dramas show very well character development.
+ both are connected to past events

If you enjoy the cases in Signal you are bound to enjoy Burning Ice.

It's similar from the game aspect and how it can affect the players of this game,, How dangerous it can be and How it can change the person's life

Obviously adapted from the same manga. A lot of things changed coz it is set far after this drama. Worth checking out atleast
-leads are all eye candy.
-fl are both cute

Both programs address the topic of psychopathy and / or social disorders.
Suspense and thriller theme in both.

They are both very similar, both have similar female characters which they are best friends and they always go out for food, talk about love stories, and their friendship is built to be more and more powerful...

Though one is korean and another is Chinese these dramas have a lot of overlap.
Both are medical dramas with the MLs having a mentorship type of relationship growing into romance.

it's the same set but different actors and actresses with more disgusting characters and events.
if you liked sky castle you will most definitely like penthouse. it even has a s2 and s3 now lmao.

The four characters are individually contrasting in both the dramas
RUN-ON starts by describing how it dovetails four antique characters-Loser,Psycho,Trash and Crazy . Trot has four leads as well with pretty similar characterizations. If you like SeoDanHa from Runon you'll like the counterpart as well.
Both are not over dramatized with witty and reasonably realistic dialogues.

Both movies portray life segments of melancholic, lonely and thirsty for love cops and have the same artistic and intriguing noir vibes, with stunning neon-textured cinematography and magnificent night shoots across city streets.

-They are both crazy shows
-ML is obsessed with the FL
-ML is basically a stacker too
-Both are interesting shows that no matter how crazy they are you can't stop watching it

Both have powers this might be the only common thing but if you like this I think u will definitely like that too.

Both are centered around women, Search: WWW consist of 3 female leads who hate each other but started to become friends just like how Age of Youth girlies couldn’t recognize each other than began to be besties.

It's most similar in the play of psychological thriller sense. Although Cello is caught up between supernatural and psychological, Insane also gave that thrills and chills with it's great execution of the plot.

For me Insane is most similar to the kind of movie I imagined Cello to deliver.