Pros: comfortable, durable, reliable, and roomy
Cons: repair time
With two children having gone through years and years of school, I have become hooked on the reliability of Jansport backpacks. For both my daughter and my son, one purchase of a $50 backpack lasted them all the way through high school and some of college. These backpacks are amazingly durable, standing up to being thrown around lockers, cars, lawns, and even driveways. The leather bottoms are especially helpful in keeping books and papers dry. With four different compartments and a myriad of nifty little nooks and crannies for pens, pencils, a cell phone, a disk, and other miscellaneous items used by teenagers, these bags are also great for organization.
Jansport backpacks are great for school, but they also work great for travel and vacation. With comfortable padded straps that provide maximum ease on the back and shoulders, my entire family brings these bags on camping/hiking trips, as well as on vacations on buses and planes. There's nothing more convenient for carrying all the necessities of life, from books and magazines to toiletries and food, all in one bag.
Furthermore, these bags are covered by a lifetime warranty. This is really convenient, and helps to ensure that they will be worth their money. The only warning I have is not to send in a backpack for repair during the holiday season. It takes especially long, almost a month without the backpack, which can be a disaster.