I've got a Gunners one (babies go Guns N' Roses) and some Metallica lullaby thing.. They get a bit repetitive after a while, but then so does The Wiggles and other shit.
We have an iPod in my sons room with quite a range of different things on including these that gets left on random on a low level permanently including night time.
When he's awake I'm busy trying to give him a rock education with the real thing. I force him to endure classic rock YouTube vids on the TV.