I'm about to do it too, basically, Co Springs to East Tn. It's not the best part of the country to see. Put your head down and get through the plains, then the eastern mountains, no matter where you cross, are green, lush and beautiful right now. Once you get past them, the Outer Banks (NC) are a quiet and beautiful area, except maybe in peak summer.
I thought that too about the plains, but found that if you get off the interstate there are actually some nice things to see. I thought North Dakota was really nice, for example. Last summer on our XC trip we drive the northern tier coming home. It adds a few more miles compared with going direct but it's worth it. Central Minnesota to northern Wisconsin and the Michigan Upper Peninsula. Really pretty along the Great Lakes, and plenty of camping options. Build in a day trip to Mackinac Island in Michigan (look it up). Then across upstate New York, lots to see in the Adirondacks (lakes, high peaks, tons of nice camping spots).
Alternately, I-80 across northern Pennsylvania is REALLY pretty and very remote.
I agree, Brian, lots of good options to the north. Through the middle or across I-10 or I-40 are uber boring though. I'm too impatient to get off of those main routes because I'd rather just get there. These are the only times I start thinking about the benefit of self-driving cars.