Passport America Half Off Campground Membership
This is the membership that I use the most when we are going from point A to point B. I would say the average savings I get is $15 or more per night so it pays for itself in just 3 nights. This is a must have for anyone who travels in their RV often, you don't even have to be a full timer to justify the cost of this particular membership Note that you do receive a membership fee discount for buying a multi year membership. I bought the 3 year and saved $23!
Happy stamping and/or camping!