Roling's has the best challah I've found in Philadelphia (try their whole wheat challah!), and excellent pies and cakes, as well. The prices are very reasonable, the folks behind the counter are amicable, and the baked goods are always fresh and delicious. It's well worth the trek for those who live outside of Elkins Park--I live in Center City, and take the Regional Rail to the Elkins Park stop: Roling's is right across the street from the station. There's nothing like an unpretentious, neighborhood bakery that takes pride in what it creates and knows how to bake the old-fashioned recipes...and Roling's is definitely that. By the way, it's a kosher parve.
Pros: great pies&cakes, great service, inexpensive