Most of the times I've gone to Pittsburgh, we've stayed at the Hilton. The players will come down into the lobby and sign autographs, talk to the fans, etc. I'm not big on autographs but I had a cool conversation with James Farrior a few years ago.
Besides the Steelers staying there, the other great thing about staying at the Hilton is its proximity to Heinz Field. The morning of games you can either walk over the bridge or take one of the ferries over. And then after the game you're not stuck in that traffic jam trying to get out of the city.