It's a hard choice. The Marlins practically disassembled their team, its hard to dislike them for any particular reason. The Phillies lost Victorino - and his bush league plays were one of the main reasons I despised that franchise at the time. I wasn't a fan of Utley and Werth together who looked like they should be singing with their friends on a street corner in the 1950's, but Utley is now hurt and Werth is making big bucks for the Nationals now.
The Braves lost Chipper Jones, who I never disliked, but I would never say I liked him either. I hated Andruw Jones, but he's long gone from them.
And the Nationals are a fun team. I enjoy watching the games we play against them, because they have a very dynamic team and they also have Davey Johnson as their manager who I'll always have some favor for.
I guess, if there was a gun to my head, I would say the Phillies or the Marlins. Cole Hamels remarks a few years ago still irk me, as well as Jimmy Rollin's big mouth; and the Marlins because of how poorly their franchise is run.