As a Juve fan, I'm going through a weird stage right now.
I don't hate Fiorentina, I actually feel sorry for them. I don't think they deserve relegation - they're going through a Sampdoria-like spell right now. They have some quality, and shouldn't be performing that badly.
I hate Inter and always will. The biggest rivalry in Italy, what's more to say?
But, I FUCKING hate A.C. Milan with passion now. More than Inter and Fiorentina combined. Berlusconi, Galliani and Allegri are all sneaky, shady pigs. I hate the management down to the players. They fucking suck, they sucking fuck and I don't like them.