Let's see:
New York Warriors - Always seem to have great close games against them (aside from the playoffs in season 4), plus their QB decided to smack talk us for no apparent reason one day. Still, they are a great bunch (who we must kill...repeatedly)
Eleven Wise - If someone doesn't have these guys as a rival, they need a head check
Nighthawks - Been on the losing side to them a lot, finally won a couple of shock victories (they were shocks to us anyway)
And after last season, i think Metropolis came into our sights as well, damn dirty playoff place pinchers they are.