I'm from New Jersey and I worked in an Italian/pizza restaurant for years. I know pizza. Not to sound like a fatty, but I've been in Pittsburgh for 8 years on a mission for people to understand that your average pizza here is just all wrong (don't get me started on the bagels).
Pizza sola is the best pizza in town...aside from the wood burning oven pizza at piccolo forno, but that's different. I'm appalled by the bad reviews, really. I understand sometimes the dudes working there look...tired? maybe that's the word? But I'm not aware of any other places where you can get slices displayed in cases, just like home. The crust could be a little thinner, and they could probably have more options available on average, but it's great. Also they use better ingredients. Lastly, their housemade blue cheese for the salads is like....the greatest. Okay, done talking like a fatty. Go here for your hangover cure or anytime you won't feel guilty eating the giant fatty slices.
The cranberry location needs a little work but is still good. I think southside is still best. And it's nice that there's beer at the oakland one.