My pick of all backpacks is the Trager Transcontinental 755B. They are pricey, but the old addage, "you get what you pay for" certainly is true. What I like about the 755B is that you can use it as a shoulder bag, a backpack, or carry it by hand. It also has a seperate padded sleeve inside for your laptop plus a side pocket for a cell phone. They enlarged it to carry the current wide-screen laptops too. I have had mine for about 5 years now, and it is still wearing like iron. I consider these as cheap insurance for the computer.

More info can be found at: http://www.tragerusa.com/catalog_main3.html