The 50's music channel has the familiar classics, as well as earlier songs from that era which I hadn't heard before.
There is also a channel geared to independent truckers which I'm hooked on now. Dale Sommers (aka the Trucking Bozo) and his son Steve are great.
They talk politics a lot and are generally pro-military, pro-small government conservative in their commentary. They're good old boys with common sense.
I just wish XM had the NFL.... baseball blows goats.. I own stock in both. I figure that every car and truck will have it in 10 years. As well as GPS and video for security. Imagine carjackers "smiling into the camera"...