Gotta be interesting in NYC...Yankee fans and Mets fans having to work together. Can't imagine what it was like when the Giants and Dodgers were still in NYC...AL/TN is much bigger right now than FL/TN, but it hasn't always been that way. The AL/TN rivalry used to be one based on mutual respect - now it is sheer hatred.
Mets/Yankees also belongs on this list. That rivalry is much like Bama/Auburn. They are from the same state and their fans have to see one another every day. It gets ugly...