I vote for LelouchxCC as well, though I must admit I have a little liking for ZeroxKaren as well.
SuzakuxLelouch is fine, but as I can't stand Suzaku, I can't really support the couple much.

I like how the relationship between Lelouch and CC is growing, and I think the two will end up feeling a real need for each other, if not love, at least a really strong friendship.