On of them is Little Star, a mini chain with three locations in the Western Addition, Mission and Albany neighborhoods. I'd heard their pies were good. But it had everything going against it when I sat down: (a) it had deep dish pies on the menu, (b) it was a mini chain, and (c) it's in San Francisco (a fact not to be overlooked -- pizza in San Francisco just isn't that good in general).
The deep dish pie had a flavorful sauce and was not disgustingly heavy. I strongly recommend the personal sized pie -- which I've also enjoyed at places like Lou Malnati's in Chicago -- because they hold together well. With a large pie you often end up eating clumps of cheese and sauce. All of the other ingredients added a different element to the pie, but none stood out in a negative way. I didn't have high hopes for this pie, but as far as deep dish goes... it was solid.
Although our thin crust Little Star pie looked tasty, I was unsure how it would stack up to the deep dish pie. In short: it stacked up well. I was nervous about the onions and mushrooms in particular, but they were both cooked to perfection. I was nervous about the pie having too heavy of a ricotta flavor, but it had just the right amount of cheese. The crust was soft and thick enough to hold together the toppings. Another hit when I least expected it.