I was living in CT for '99 and I recall even in Ffld Cty, there was palpable joy and pride in UConn's 1st NC. People were happier, friendlier for awhile. I moved away permanently later that year.
I say that because I've been in Pgh for the past 22 years, and experienced the Pirates actually being decent for 3 of those years. The WC game in 2013 was the best live sporting event I've ever attended (which includes NFL playoff and WS games) and this city was in ecstasy over its baseball team being relevant again. 2nd place isn't even close.
So I'm going to say that for me, it's the Pirates. They play a more important role in my everyday life. UConn men's hoops would be #2 and UConn football has become #3. It's possible the Steelers wedge in there eventually as Pickett is fun to root for, but I despised Roethlisberger and Steelers "culture" for so long, I don't know if I'll ever really be a fan.