I've surfed Maine a couple of times and I'll actually be there again this weekend (and a couple more times this winter). In my experience, really nice people in the water, some good spots, and overall fun times. If there's a solid swell, it'll be as good as anywhere in NJ and (presumably) less crowded, too, but it's a pretty long drive up there if you're not totally sure where to find the waves. NH (lots of point breaks) and RI are super close, too.
Maine is the best! I agree with Kielsun..although I have never surfed jersey so I can't really compare the two. I second NH as well, some very popular breaks there so expect more crowds, especially on the weekends.
One thing to consider when surfing Maine is that Cape Cod blocks a lot of the swell that you might see in RI of LI. Its also no warmer than 62 in the height of summer so you're gonna need some rubber. That said, Maine has more true point breaks than most of the east coast so the possibilities are literally only limited by how much you're willing to explore. And some are more than worth the 8 hour drive from NJ.