Any dramas where the female lead chose the best friend of the male lead over the male lead in the past. Some time later, they meet again. The male lead is cold to her for hurting him. The female lead and best friend aren't together anymore and she falls for the male lead. The best friend tries to win her back though.
The Imperial Doctress has most of the things you're looking for. Princess Agents, Jealousy Incarnate, Sound of the Desert, and High Society (more the second couple) also have some of the elements you're looking for.
Irusu:
