I've lived in IL basically my whole life. I was born in the UP, and so I have an affinity for my birthplace because I think it is just a special part of the country (fully grant my bias). But my dad got a job in the suburbs of Chicago, and so I grew up in the Chicagoland area. The Cubs, Bears and Blackhawks are my teams, but my grandfather was a big Tigers fan. So like I said I don't really have a second team, but I want the Tigers to do well because of the memories I have tied to the team (those mid 90s softball lineup teams were fun).
And I understand the rivalary, and I've enjoyed the good natured ribbing about it.