I can't say that I do. I grew up in Illinois, so I'm supposed to like the Bears, but I don't. If Buffalo dissolved altogether and did not move to a different city I would maybe become a Vikings fan, having lived in Minneapolis for six years and loving the city. I did root for the Saints when they went to the Super Bowl. I thought it was a great story and wished the city success after the hurricane. When the Bills aren't playing I root for underdogs, as long as it's a game that doesn't affect Buffalo's season. I also root for whoever is playing the Jets. I HATE the Jets.
In baseball I'm a diehard Cubs fanatic. But I do have a second team in the Red Sox. Prior to winning the World Series twice in recent years they were sort of the AL version of the Cubs. I think it's easier to have a second team in baseball, where interleague play isn't as substantial or consequential.