Basically the most hated sub-genre of love triangles. Y'know like Love Alarm or The King in Love.
You have watched way more dramas than me, so I will try to pick something from your "plan to watch" list
Dream High (sort of)
Jealousy Incarnate
Meteor Garden
Missing You (they are relatives, 2012 drama)
Chicago Typwriter- best friends in their past live - the two meet again in their current life
Lion Pride - best friends
Protect the Boss - Cousins who are business rivals as well (they would never admit it, but they like each other like friends)
I will not just do what Kira says and Black Devil and White Prince - best friends
Naked Kitchen - she has an affair with a guy which happens to be a friend of her husband (she did not know that)
https://kisskh.at/25676-nothing-to-lose - best friends
https://kisskh.at/51207-my-girl - best friends
https://kisskh.at/23281-heavy-sweetness-ash-like-frost - half brothers
https://kisskh.at/39301-dr-cutie - half brothers
https://kisskh.at/395-she-is-nineteen - brothers
https://kisskh.at/2452-into-the-storm-2004 -brothers
Try this thread HERE
For bestfriends love rivals:
The Sand Princess
My first first love (friends)
Just Between Lovers (coworkers)
My country: the new age (best friends)