I guess it depends on what they were listening to before!

But since most of my friends listen to rock, I'd recommend something that is in a different genre but not too strange that it isn't bearable.

For instance: "Atmosphere" (You or Puppets or Guarantees)

Or, in a completely different genre: Kane! Cause they're awesome. And most of my RL friends don't know them but I think they'd like them... (Spirit Boy!)