We (wife and I) don't often drive through campgrounds, but we definitely would be number 3... slow rubberneckers. I drive through campgrounds at idle speed because of kids, and since we are driving through the campground to check it out... we rubberneck! lol
While are are camping, we certainly go for at least one walk to check out the campground. And of course to hobnob with fellow campers, and we always see one or two setups that spark my interest - and campers are usually only too willing to talk about their rigs!