Cape Henelopen in DE is nice, it's more of a campground than roughing it - but there is no pool, it's near the beach and you can ride your bikes too. We were there on a weekend and there were kids, but they were pretty well behaved and not so bad (guess cause there wasn't a pool)
French Creek State Park in PA is really nice - dog sites and non-dog sites available. More 'woodsy' sites but they have running water.
World's End State Park is probably too far - but that's very rustic - it has a swimming hole which is a spring starting a creek - it's beautiful and during the week not too many kiddies - and you can rent (non-dog) cabins year round - very romantic.
We haven't been camping much since we've moved to SE PA, so I haven't been many places. We hope to go more this summer though. Any places I should particularly avoid?