There's so many ReinAi-ists in this thread I'm almost afraid to jump in. I've always found 'shipping to be good fun though so... here we go.
#1 has to be
TakaGaki all the way for me. I think you have to look below the layer of cute and fluffy to find the interesting aspects of this pairing. The interesting thing about them is that they make it
look easy, safe and completely stable which may equate to boring to some but really, what we should realize is that "ordinary happiness" is one of the hardest things in the world to achieve. How many people out there are "simply happy" with their relationships? I don't know many or any, so it makes me think what goes on behind TakaGaki in a universe where they're together.
It's not their supposed prefection that makes me like them as a couple but the possible hidden flaws that are so much less obvious than the ones other pairings have that make them appealing. I'm a fan of the subtle, what can I say?
GAM. Who can forget the utter win that is (yes, present tense. They still win.) GAM? Do I need to explain this? I hope not. I'm not going to. I just love them.
TanaShige is another one I like though it seems to be one of the underrepresented pairings. Not surprising considering the scant glimpses we get of these two interacting but when we see it, there's definitely potential.
Have to give honourable mentions to GakiKame, KameShige, GakiShige and ReinaxMaki too.
Oh and since no one has mentioned any of the Berryz工房 or °C-ute pairings, I'll do so as well.
First has to be....
MiyaSaki (thanks to
rokun). It really helps that they seem really close and thus offer lots of material to take off from. Also this is the pairing where I can see Miyabi doing the admiring first, whereas with others, I see someone falling for Miyabi first. Also, this is one of the only Captain pairings that works in my head though maybe this would change if there were actually others.
Airi and Nakky... which has never been written but gosh darn it, I want to read this. I just do. It'd be awesome and Nakky deserves some love after they rhymed her photobook with 'tacky'. Okay, so I can't really say much more than 'it'd be so cuuuuute!' but that's a good reason.