I know, what's a south philly boy directing folks out of philly for? Because I have never had such pizza as my wife (littlefromage) has had in Trenton NJ. Wow! Delorenzos Pizza on Hudson. Be careful, there are two of them. I think the family had some issues and I hope no one was hit with a pizza pan or slicer, but the one on Hudson street is amazing.
Make sure you empty your bladder before you go because no bathroom. I also recommend that you BYOB. Its down to the basics at the D - but you'll get hooked!