Kalinda/Alicia until they … (spoiler) stopped being friends :(
Choi Kang-hee and Wang Ji-hye in Protect the Boss
Nikita and Alex in Nikita (lol this show)
And I wish I got to see more of Hye-sung and Do-yeon’s friendship in I Hear Your Voice, but that wasn’t really a priority in the show :(
I really loved Jin-sook and Soo-min in Heartless City and wished to see more of their friendship too, but again, their relationship wasn’t really a priority in the whole scheme of things :(
Oh! Another one: I stopped watching halfway through Alice in Cheongdam-dong, but I really did like So Yi-hyun and Moon Geun-young’s characters’ friendship from what I saw of it, though I’m unsure if it ended up being the typical love rival relationship down the road.