You've come a long way since your middle school crush wrote "4-EVA" on your canvas Jansport. But there's no denying the practicality and comfort of a roomy backpack when it comes to lugging your gear. Enter the Fjallraven Kanken. This Swedish beauty will fit all your stuff—from books and a laptop, to gym clothes and a canteen, to a Dopp Kit and some weekend wear. It comes in a range of colors, but we'd suggest one in gray or black—it'll hold up better against the elements and the whims of fashion alike. About $60 at Tamarack Outdoors.
Avoid back pain by packing the heaviest items in the bag closest to your back, and wear both straps to distribute weight evenly across your shoulders. (Source: MedicineNet)