Via Max Power, a fine New York Times article: "Pizza 2002: The State of the Slice." (It probably requires registration, but what the heck?) It's filled with local, New York details and cheesy goodness:

Many pizza lovers credit the Ray's Pizza shop at Avenue of the Americas and 11th Street with popularizing the half-pound slice, though Columbia University students often cite the gigantic slices at Koronet, at Broadway and 112th Street, as the original good-value portion, at nearly 15 inches long.

I gotta stick with my Jersey roots and cite Seaside Heights' own Sawmill as my favorite jumbo-slicetaria, as anecdoted by Big White Guy in the tale "Old Barney and the Sawmill":

After Ronnie showed up, everyone piled into the car, and they took me to Seaside, to a neat little restaurant/bar called the Sawmill Café — literally a piece of their personal history. They were all excited to show me the place and explain the good times they'd had over many, many years of visits there. [...] They ordered a pizza for the six of us. I wondered if it was going to be enough, until I saw it. The thing was freaking huge! It had to be at least 24 inches in diameter. It was different than the kind of pizza I was used to: nearly flat, with lots of cheese and sauce over the pepperoni.

Mmmm...big pizza, big Skee-Ball scores, big hair...god I miss Summer down the shore. At least NJGuido saves all those memories for me.