Many debates about this topic before. There was a link to a survey posted about this topic on the MAC board.

http://knowrivalry.com/rivalry-survey /

The survey asks you to rank the biggest rivals and then asks questions about what makes them rivals. I took the survey specifically for men's basketball and my answers would definitely be different if I approached it for a different sport (or the school in general)
Yet even answering with basketball in mind, I felt my "non-basketball" feelings impacting my answers.

To summarize, all of our rivals suck in their own unique way.