We had our long road trip from late June to mid July. Experienced 11 hotels. Three hotel chains, one independent B&B. The Winner is: Hampton Inn & Suites Pittsburgh-Downtown.
Perfect in all aspects that are important for us:
Professional and cheerful receptionist;
Sparkling clean no matter where you go;
Good breakfast-Same standard Hampton breakfast, same cheese omelet, same sausage, but they were prepared just right, fresh and soft, enjoyable);
Functional bathroom - ample room, with bars and hooks, ample counter space, water pressure from the shower head is just right. Plus quiet, efficient ventilation;
Has in-room safe;
Comfortable, sufficient lighting;
Nice firm mattress with good beddings (without odor of other people, nor detergent);
Value: the price was shockingly reasonable for a downtown hotel with big, gated free self-parking;
Room is much bigger than other downtown hotels too.
The good thing about downtown is that there are usually many good restaurants within walking distance. We walked 3 minutes to a wonderful restaurant that night and had a good time.

Loved this hotel. It was centrally located to downtown and a number of places were in walking distance. This hotel also offered free parking which was an extra nice bonus. The staff was friendly, helpful and welcoming. The breakfast was good and the rooms were very nice.

If you're coming to Pittsburgh to ride the GAP and return by Amtrak, this Hampton Inn is a great option! They'll let you park your car there for free for the whole time you're gone if you have a room booked at the end, and since the train pulls in at midnight it makes sense to stay overnight and drive home the next day. It's a two minute bike ride from the train station, and in the morning you get a full breakfast, and an indoor pool and HOT TUB! All that for $30 more than the parking fee at the transportation center!