Before anyone comments, let me save 당신 the time; Yes, I'm aware that (1.)They're gay and (2.) They're a fanon/crack couple. I still 사랑 them all the same.
if it can be an 아니메 couple then it would be: Tomoya and Nagisa (Clannad and Clannad after story) if it's a game couple then: Kluke and Shu (blue dragon) and 만화 would be: Candace and Jeremy (Phineas and Ferb)