PA is nice, if a little boring. Not much out there but rolling hills. It's certainly a good bet if you want to remain less than 2 hrs from EWR.
There are also some OK places along the Jersey Shore worth looking into. Princeton isn't too bad. Everywhere in Jersey, however, you'll here the sucking sound of your income being drained away by property taxes.
This is an opinion, but check out the hudson valley area of NY. Granted NY has high taxes, but I don't think nearly as high as NJ. If you don't mind a small town setting, check these areas out. They're all from an hour to an hour and a half from EWR:
Warwick, NY (good schools)
Goshen, NY
New Paltz, NY (College Town)
Carmel, NY (in the Housatonic region, but nice)
Some people live a little further abroad, about a 3 hr drive, and hang out in the Berkshires of MA or Glens Falls/Saratoga NY region. Saratoga is especially nice, as you can hit the Adirondacks or go into Vermont on your days off. Good schools and outstanding recreation opportunities.You pay the price with the long drive, but it is a positive space car. Beats commuting by plane any day.
Good luck. It is a real challenge finding a place that's good for the fam that's affordable around EWR. I've driven all over the place. PM me if you want to know more.
Seeya, Navin