Macbook Air. I've been really happy with my decision to go with the Air over the Macbook Pro. The latest line is definitely powerful enough to be a primary computer for users who don't need more processing power than you'd need to play or stream video smoothly.
So well named, the "Air" is light as a feather. Imitations: they're on the horizon. See the new copies from HP to Lenovo to Dell. Price matters. The Air is the best, but the competition is at a much lower price point, and that may be the secret.