You won't find as good of riding scenery as a train. They go places where the highway doesn't.
If I ever get the chance, there's a steam engine in Colorado Springs I want to take a ride on. Its an old mining train that goes up through the mountains. Gotta be sweet.
Had a blast on Amtrak, NYC to New Orleans. Someone had a guitar, 2 or 3 people brought bottles. After the bar closed, we stayed up and had our own party. singing songs and getting drunk. A hell of a good time.