The most reliable internet service would, in my opinion be a satellite based internet,which is what I use...
The "basic" system cost is $59 per month for connectivity and you can either access the satellite with a tripod mounted dish or an automatic dish mounted on the roof of your coach.
The smallest dish of this type runs $4995 installed and pretty much is "push a button" to connect.
In my case, I was used to "broadband" speeds at home,so I opted for the much larger dish and thus a $79 service plan...
Datastormusers.com is an excellent forum for you to see the different kinds of satellite internet users and the issues and concerns they deal with on a daily basis...
Just like anything else where there are choices, some folks sing the praises of the tripod mount and others may sing the praises of the automatic mount.
As I travel some without the coach,I happen to also have an aircard which I can also use in the coach if there are trees that obstruct my view of the satellite...
For the most part, I am able to ask the "right questions" of the campground as I make the reservation and then can get a suitable site.
Here's the larger dish when it was installed on my old coach....they're not ALL this big!!