Must watch K-Dramas & Movies Please

If you want to watch lighthearted romcoms, then I'd recommend Thirty But Seventeen, Weightlifting Fairy, School 2015, When The Camellia Blooms, Shopping King Louie, One Spring Night, Extraordinary You etc.

If you can handle a bit heavy ones not necessarily sad but less rom more action then Alchemy of Souls, Kingdom, Little Women, Flower of Evil, Rebel - Thief Who Stole The People, School 2013.

Then there's ones super popular like Goblin, DOTS, Crash Landing On You etc which are over hyped but still worth watching.

currently airing
I advice you watch

Red Balloon
and
you can also try

The Mafia, the Salesman 2007 movie
both lead Lee Sung-Jae and Seo Ji Hye in that film

then another drama
I recommended is

The Interest of Love (2022)