My Little Happiness (you saw), but it is my top.
Sweet Teeth - sweet romance with multiple couples
Hello, the Sharpshooter - healing drama with slow burning romance, but the love of leads is very strong.
My Queen - funny adventure, wuxia, nice romance, many likable characters
You Are My Glory - sweet romance
These had very good and strong romance...I really enjoyed these so much.
https://mydramalist.com/7925-the-virtuous-queen-of-han
https://mydramalist.com/53117-cang-lan-jue
https://mydramalist.com/26385-three-lives-three-worlds-the-pillow-book
My Fated Boy was lovely in every way.
Go Ahead--not just a good romance drama, but an outstanding drama overall
Professional Single (show has problems, but this is one of my favorites)
A River Runs Through it (another favorite)
Love Like the Galaxy (I'll watch this show again and again)
The Story of Ming Lan, probably my all time favorite Cdrama. A long, satisfying story with a slow burn romance that is well worth the wait.
A Dream of Splendor (admittedly, I'm only up to episode 13, but the growing relationship and action sequences are really good). https://mydramalist.com/76169-bian-liang-meng-hua-tu