Meeting a friend who's visiting and staying in the Park Slope area--all three are fairly inconvenient, so location isn't really a factor. I only include that I'm meeting a friend to say that "experience", while a distant second to the pizza, does count.
Of the three, I've only had Roberta's from their mobile stand around Manhattan, which I hit every time it pops up--love their crust, and visiting their brick-and-mortar has been high on my list for a long time. As far as composed pies go, Paulie Gee's grabs me the most with their creative topping combinations. On the other hand, I love the ethos of Lucali, as well as the BYOB.
So which would you pick?
(as an aside, are any of these three near a street with enough cab presence that we can snag one reasonably quickly afterward?)