I absolutely love the History Center. Maybe it's my love of Heinz ketchup that draws me in... But there's so much more! If you love Pittsburgh, you are seriously doing yourself a disservice if you don't visit this museum. It's basically an "I Love Pittsburgh" museum, with lost of history of course.
Clearly my fave exhibit is the Heinz Ketchup one, with lots of facts on the company, as well as some great visual items (hello tall statue of ketchup made from ketchup bottles). If you love Mr. Rogers, you'll also love the permanent exhibit with lots of artifacts from the show (like the castle!). There's also a dedicated sports exhibit that any black and gold supporter loving nut will love.
I don't think there's one temporary exhibit I've missed in a while. I LOVED the 1960's exhibit, had fun with the Toys show and can't wait for their new prohibition one this winter. Add in the fact that this is a great wedding or large event venue (they host a wide array of fantastic events).
It's not just for the adults either. They have a cute kids area with lots of activities and older kids will be interested in the interactive exhibits and honestly probably be interested in the rich visual content they have.
Seriously, if you're visiting Pittsburgh you will still love the museum, because to know Pittsburgh is to love Pittsburgh, n'at!