How about East Harbor State Park. Very large state park with 550 sites. The "pull thru" electric sites in section "B" are very large. The full service sites in section "C" are also OK. But the back-in sites in section are very tight and short. Near by you have Marblehead, Put-N-Bay / South Bass Island....You can either take our bikes over on the ferry, rent a golf cart once there or take your car over. The State Park campground (South Bass Island) is very tight and is mostly for tents and smaller RV's. Here is a link to some
pictures of that area