I can't imagine cheering for any other NFL team besides the Steelers. I've dragged my wife into my sinful ways to watch them play in San Francisco and New York, and last year took my 3 boys to a game in Phoenix. The kid in the middle claims to be an Eagles fan, but I'm working on him.
I've been an SF Giants fan since I was a little kid and could pick up KNBR late at night in SE Idaho. I've sort of rediscovered them the past couple of years as my second oldest son has really gotten into baseball and watches games with me.
I don't have an NBA team. I'm just not a basketball fan, pro or college, and really couldn't care less about it.