Having grown up in Syracuse, the area really is what ever way the wind blows. In the 1990's it was Bills territory, followed closely by the NYG. By the 2000's it became more spread out with the Giants, then Bills and Jets holding the most fans, followed by a whole lot of randomness.
I actually knew a lot of people who followed the Eagles because of Donovan McNabb (or so they claimed), but following his departure from Philly that fad has faded.