Duffel Bags

The traditional duffel—minus wheels and pull handle—is lighter than its rolling counterpart, easier to store (no rigid parts, so it folds up smaller) and friendlier to your budget. It also offers huge capacities—several models available at REI provide over 130 liters (8,000 cubic inches) of space. Zip your pack inside one to transport it on an airplane.

Best for: climbers, college students or any traveler on a budget.