I've had XM radio in my car and my house for almost 2 years now and absolutely love it. I also use the online streams when I'm listening to music at the office or in hotel rooms. Deep Tracks and Comedy 150 are my two fave channels
Slick mentioned that you might not need it if you live in big city...well, I live in Atlanta and I just got tired of hearing the same songs AND annoying commercials. I'll never go back to standard FM....