This would have been easier if the question was which ACC program do you detest the most (or staying with the theme, second most). Answering that question is easy - FSU. I spent my freshman year in college at Miami and that was all it took to imbue me with a strong hatred of all things FSU.
Answering the question at hand, I guess Miami. Honestly, though, all that means is I will not be disappointed if Miami wins the Coastal. It is not an active fandom.
I actively root for the two schools that handed me degrees. That is enough.