In northwestern Vermont, I'm personally familiar with Apple Island Resort (North Hero) and North Beach campground (city of Burlington). I think North Beach has full hookups, but if not they at least have water and electric. Of the two, Apple Island is probably the nicer/fancier but both are acceptable. North Beach itself is lovely (and popular during the summer with day use people), and the park and campground are right on the bike path.
Lake Dunmore Kampersville is reported to be very nice, by a good many people.
None of the Vermont state parks have hookups of any sort, but the ones I've camped in have been nice enough (if rustic).