I'm from Pittsburgh with is OK as far as dog friendly goes. Most of the major parks, both city and county, have off leash dog areas. Many of the remaining parks permit dogs on leash. I've also noticed that the parks the permit dogs have also installed "doggie cleanup" stations (a poop bag dispenser and lidded trash can). That doesn't mean people use them, I've seen piles of poop right beside the cleanup stations, but at least they are available.
Outside of Pittsburgh, I'd have to say the most dog friendly town I've been to is Gettysburg, PA. Many of the shops there have signs in the windows stating pets are welcome. They also have this adorable dog boutique called Island Dog with a very friendly shop owner who sells mostly hand made items ranging from slate painted doggie pictures to biscuits. I got Edan's and CJ's car harnesses from this store.