I vote for Kaoru and Tamaki-sempai.
Tamaki is simply so funny. His little outbursts are always random or give you a good laugh. Whenever he gets depressed, I can't help but smile. I really didn't like him at first, but he grew on me. Particularly because of his overdramatic freak outs.
Kaoru grew on me lately. I don't know why. I simply like him slightly more than Hikaru. Kaoru's a bit more understanding, but he can still pull of a good practical joke.
