Itachi and Sasuke aren't your typical Cain and Abel characters. I mean, Itachi used to be the favorite, but then his family turned away from him as soon as he showed something else than perfection. And then Itachi decided to fully turn the tables by himself.
Anyway, their bond is all twisted and unhealthy and destructive, so of course I like it. XD
(I like Itachi and Kisame relationship better, though. Sasuke doesn't understand his brother at all, but Kisame and Itachi both understand and don't understand each other.)