Uh... I think that at first my fav. was Kangteuk? :O
But soon enough I changed it to Hanchul, just because I'm in love with Heechul so... yeah.
And I still concider it my fav. even though now I mostly read/write/think about QMiMin~ And I don't have a fav. couple from these three- as if, I love QMi and QMin the same and I kinda like MiMin even though they're not really compatible, only when they're with Kyu... XD
And I also really love Eunhae and Yewook, and Siry~ [that is- Siwon/Henry~ my friend started to think about them as a couple and when I thought about it they really are compatible<3 And she invented the couple name, which is really cute XD]
But my favorite is Hanchul.