I posted a brief message about this place in a discussion on the NYC/Outer Borough boards and was asked to post a comment here.
There's been a lot of discussion as to what's the best pizza where. The pies at Frank's Pizzeria in Ambridge are my gold standard. Fresh dough - not too thick, not too thin. An amazing sauce, not too sweet or tangy, light, but not flavorless. The cheese under the sauce. And the pepperoni, some chunks an inch thick. Definitely a family run business, the grandkids have been spotted working in the shop now under the tutelage of Frank.
If you're in the Pittsburgh region, this place is definitely worth checking out. Here's the info...
618 Duss Ave
Ambridge, PA 15003-2022
Phone: (724) 266-2890
BTW - for what it's worth - on the Pittsburgh Citysearch board it's received all 10s in the user ratings and was nominated for the best pizza in Pittsburgh... for a little shop in an old, run-down mill town, that's not half bad.