Since we had an un-Even amount of characters I decided to add all three of these in a pick. Once one of them is eliminated, there should be an even amount of characters to continue with one against one picks. So here are you choices:
If you want:

Rin-ne & Haruhi OR Haruhi & Rin-ne~
Rin-ne & Hatsune Miku OR Hatsune Miku & Rin-ne~

OR you can have

Hatsune Miku & Haruhi OR Haruhi & Hatsune Miku~

^_^

I choose haruhi and hatsume miku ^_^