I like VLC for the times Quicktime won't play something. Fetch Art can help speed up acquisition of cover art for iTunes, if that's important to you. A utility like MacJanitor, Macaroni, Onyx, or Cocktail is a good idea. Since it's a laptop you might want to try SideTrack, which is a driver for the trackpad. It allows you to do a lot of crazy stuff like scroll by touching the side of the trackpad. It's beta, so don't expect perfection--but it's still neat.
Apple takes pretty good care of you with what you get out of the box. Is there some specific kind of software you want to know about?