James got me hooked on Booq bags about two years ago and I’ve never regretted my purchase. I have a Booq backpack that carefully caresses my Toshiba M205 and would hold any 12-inch notebook quite capably. In fact, I use it to carry my Samsung Q1P and have plenty of spare space for external batteries, optical drives and more.
I just read that Booq introduced the Vyper exo for 15- and 17-inch MacBook Pros; the bags range in price between $175 and $195 and provide two layers of dense foam protection. Although I prefer a backpack model over a "suitcase" look, there is a shoulder strap as well for the Vyper exo. Also included is Booq’s TerraLinq™ service: essentially a unique ID for your bag that you register with Booq to aid in returning a lost bag. I especially like the way you can use your notebook right in the bag as well.
No, no, I’m not going to get all "Mac-centric" since my recent purchase, but you’ll be sure to hear me share "Mac and mobile" stuff if I find something interesting. In this ‘case’ (heh!) Windows notebook owners can also find a quality product from Booq as well; mine is easily the best bag I’ve ever owned.