New Jersey has the most diners in the world and is sometimes referred to as the diner capital of the world.

The state is home to many diner manufacturers and has more diners than any other state: over 600. There are more diners in the state of New Jersey than any other place in the world.
A map of NJ Diners is maintained by this guy:

    "I am maintaining a field checked New Jersey Diner map (July 2008 update). Every blue dot is a diner I got. Every red dot is spot where there is a diner that I have not got -yet. I have made and will continue to make repeat visits, but after the first visit the diner is in the data set.

     Hit kpatrick@iup.edu if you want to write to me about your Jersey diner experience, tell me your diner history, discuss diner manufacturers, or just talk Jersey diner. If I don't respond in a timely fashion, you can find me in New Jersey, second traffic circle to the left. Look for the neon sign that says, 'DINER.' I'll be at the counter."

Cape May holds the distinction of being the oldest seashore resort in the United States.

New Jersey has the most dense system of highways and railroads in the U.S.

North Jersey is the car theft capital of the world, with more cars stolen in Newark than even NYC and LA put together.

City Data Crime Statistics for Newark, NJ

In 1914 the New York Tribune Offered Greatest US Newspaper Premium Ever - Lots of Land in Beachwood, NJ Along With Newspaper Subscription.

In November of 1914, the New York Tribune, cooperating with Mr. Bertram Chapman Mayo (founder of Beachwood) issued an "Extra" announcing: "Subscribe to the New York Tribune and secure a lot at Beautiful Beachwood. Act at once, secure your lot in this Summer Paradise now!" This was the greatest premium offered by a newspaper - nothing equal to it was ever attempted in the United States.

New York Tribune – Original Subscription/Lot Promotion Booklet

New Jersey has the highest percent urban population in the U.S.

The only state that has had every one of its counties deemed "urban" as defined by the Census Bureau's Combined Statistical Area. New Jersey Population Map

New Jersey has the highest population density in the U.S.

As of 2006, New Jersey is the eleventh-most populous state in the United States, and the most densely populated, at 1,174 residents per square mile (453 per km²), which is 13 times the national average.