I have taken several camping trips to Colorado in a variety of vehicles, including motorhomes and camping in tents. The campsites I remember fondly were ones without hookups like Robber's Roost near Winter Park and The Crags at 9000 feet elevation south of Divide. As far as the areas you mention, I've been to Breckenridge and unless you are avid skiers there in the winter or fans of Rodeo Drive I'd bypass it. It is a pretty upscale ski town where people go to watch for celebrities (my opinion). The Durango/Silverton area is famous for the narrow scale railroad that I've never ridden, but is supposed to be fabulous for the experience and the scenery. Also you're not far from one of my favorites, Mesa Verde National Park down the road from Durango near Cortez. It's an experience not to be missed. There is a NP campground there. Other places I've been are Rocky Mountain National Park north of Boulder with a circular drive around the park reaching over 12000 feet and into the tundra above the treeline. Spectacular views. In Colorado Springs is another don't miss attraction, the Garden of the Gods. This is a spectacular area of beautiful rock formations and will make for great pictures. Nearby is Pikes Peak which I've passed, but never visited. You won't want to drive it with your PC and the cog railway is usually booked for the next 3 or 4 hours, so plan ahead if you want to take it. Also worth seeing on the western side of the state is Colorado National Monument on the way toward Arches NP in Utah and in the NW corner, Dinosaur National Monument. The one place I personally recommend against is the Royal Gorge bridge. This is touted as the tallest suspension bridge in the US, but they don't tell you it's just a wooden board bridge built way off of any main highway as a tourist trap. It's got an inclined railway, a cable car over the Gorge, fast food and souvenir stands, and tame deer that will stick their heads in your motorhome to beg. For an engineer who'd always heard of this wonder, it was a major letdown. Hope this is of some use to you.
Jerry