Kdramas that have become widely popular and broken into the mainstream.
Both stories deal with themes of class struggles and income inequality. They also have thrilling, dark, & bloody elements.

These two dramas will warm your shriveled dark heart and you will walk away with a new perspective on life.
Both dramas are set in college and demonstrate the beauty of youth, with a lot of great comedy on the side.

Go Back Couple is a bit more serious, focusing on extremely realistic relationships, while Weightlifting Fairy Kim Bok Joo revolves around themes of coming-of-age and chasing your dreams.

Witch's Court and Return both have a strong kickass female lead
Return has one main case with smaller, individual cases, but Witch's Court has several separate cases.

Both male leads are some kind of CEO of a company
Both female leads want a job under the male lead's company
Both female leads are 'different'/act 'differently'