Laptops don't have "good" sound, they just have sound, lol. The MB has crappy sounding speakers, but thats not my issue with them. They just aren't loud enough to me. At full volume, I can't watch a DVD movie comfortably on it, the dialogue is too low to hear. The 17" MBP has extra speaker drivers in them, so they were definately louder.
In either case, a nice set of headphones or portable speakers or something would be a good idea.