Our favourite WM overnight was in Cody Wyoming. Great couple of nights, encouraged and within walking distance to several attractions such as the dinner show, rodeo, old town etc. HD, Lowes, Costco, Samsclub, small restaurants with large gravel parking we've frequented. There are tons of places to pull over for the night. Some towns like Tomball Tx, actually have free sites for up to 3 or 4 nights for your use as well. Fairgrounds, City/town/county parks are usually low priced and sometimes free. Also security patrolled rest areas that are not main hubs can provide a great O/N during your travels.
We also have had quiet nights at churches mid week, small airports with permission, Welcome centres, some with water and dump facilities. Many shore fishing locations in low density areas.
Freecampsites.net, Casinocamper.com, Ultimatecampgrounds have been our mainly go to apps/websites when travelling and not wanting full CG facilities.
There's lots of places out there with a little thought, research and some consideration that you are not likely to intrude or annoy locals.