Well over 100 channels of crystal-clear commercial-free music. Well worth the $10/month (I pay an annual fee that works out to about that per device). And there is a fairly large selection of news/talk stations if you don't mind the commercials. And I haven't listened to one second of Howard Stern (another talking point of the anti-satellite radio crowd).
Some of my favorite stations are The Loft, Outlaw Country, Yacht Rock, Willie's Roadhouse, Deep Tracks, Classic Vinyl, Lithium, 1st Wave and at least a dozen or so others. I'm sure there's a few hip hop stations but I've never listed to them.
My first XM radio was a boom box. It was great. I could carry it around the house, in the car, everywhere. I finally had to stop using it because the LCD was no longer readable.
I now have a little refurbished unit that XM sent for free. It plugs into the house stereo system.