There are so many types of RVers/campers that it makes this a hard question to answer. Vacation types with kids want it all......travelers overnighting aren't to picky price is a big thing, Snowbirders staying for months have other needs. I thionk you would get better answers if your question was more specific, otherwise you are going to get answers from "Parks phooy I boondock" to "I want breakfast and a paper delivered to my door every morning".
Online reservable. Cost per night. Pictures of site and map of entire camp ground online (usually a given if you can reserve it online). Someplace within about a 4 hour drive away (200 miles one way).
I don't care about things like 'wifi', 'cable tv', 'pool', 'play ground'.. As, I don't go "camping" for those kinds of things, and I'd prefer to avoid the places that do offer those things in general.... Not a "dig" on those that do... That's your privilege and choice to do... Just not my thing..
So, I go to our State Parks pretty much all the time.. They offer what I'm looking for and don't have what I won't use in the first place..
We have a really nice SP system in Wa State and in the last 10 years of doing this, we have pretty much gone to all the ones that have at least electric hookups..
So, I guess that's our minimum requirement... ELECTRIC hookups.. We can deal with no water or sewer for over 5 days! We just need that electric!
That's just what works for us!
*Anything I post is for entertainment purposes only and what usually works for me.. Your Mileage May Vary..