Which characters from a different anime can be a good pair(couple)?

I always thought about Ririchiyo from Inu X Boku SS and Ciel from Black Butler. They seem alike in many ways to me. <3
~Dino

zero and ikuto zeruto

Take Slayers, Juubei-Chan, Dragon Half, Master of Mosquiton 99, & Full Metal Panic Fumoffu; The main girl is a b**ch & the main guy is a brain-dead moron. This pairing works out wonderfully, so you can swap the girl of any of these with the guy from any of these.

France and Tamaki! XD

Izaya X Kyubey would blow the world away XD.