Ehh, lemme see.
One I'd actually like to see is Akane/Ryo Saeba. Yes, I proposed a pairing with AKANE.
Reasons? Many.
One, Ryo would drive her absolutely nuts XD
Two, anything she can do to Ryo, Kaori can do better (she once shot him with a bazooka - repeatedly - in a jealous fit).
Three, Ryo can and will hit on every hot woman in Nerima. And probably screw them, as well. FEAR THE POWER OF MOKKORI!