Pizzeria Regina in the North End of Boston has the best pizza. I've been going there for pizza for about 40 years now, so I know. And they've been open since 1926, so they know what they're doing. Here's another sign they know what they're doing, and they're the best. The original location at 11-1/2 Thacher Street is small and crowded with tables, so there's only room for a couple of people to wait inside for a table. People will line up outside on the street, for a half-hour or more, even on a cold winter night with temperatures in the twenties and freezing winds blowing—and that was before they added a few strong heat lamps under the awning just a year or two ago. And the place is also well-known for brusque and even surly waitstaff, besides being cramped, crowded, and noisy. As they say in Boston, that's paht of its chahm.
The pizza itself is thin-crust, with a thick outer rim that's sometimes a bit burnt but somehow never too dry. The toppings balance the floppy-thin crust: the sauce is thin with just a bit of bite, the cheese isn't too heavy either. The sausage is fantastic.
So now here's the thing: the best pizza in the world is highly dependent upon, but not limited to, your childhood experiences and nostalgia. You can learn to love other pizza when you grow up, but I believe your taste in pizza is always strongly influenced by what's familiar from your youth. That's the only explanation I have for people who, say, have had pizza in both Boston and Seattle but somehow prefer Pagliacci's decent-but-nothing-special pizza in Seattle to Regina's superb pizza in Boston. Of course, the Seattle-raised people would take the opposite view, not seeing what the big deal was about Regina's. (But they're wrong.)
My favorite pizza places in Seattle tend to be the ones closest to Northeast-style pizza: Piecora's is pretty good, Tutta Bella is different but also very good, and I've been very excited by the opening of Big Mario's, which is really good and fairly authentically NY-style. I still have love for Bob's Pizza in my hometown Nashua, too. But growing up, going down to Boston to Regina's for pizza was always a special treat. Sometimes my parents would even decide to go there after we'd spent a day at the beach in Ogunquit Maine, adding an extra couple hours of driving to the day, just because it was that good. And so I'm happy that today I get to make my now-annual pilgrimage down to Boston for the best pizza in the world.