When you choose a backpack, there are two things to watch: how comfortable is the harness, and how useful is the bag. Backpacks need to match your activity - are you going hiking, camping, mountaineering, traveling, paddling, fishing, hang gliding or just off to work or school - the optimal backpack design will be different. Ideally you find one that is comfortable, matches most of your activities, is rugged and cleverly designed. There are also backpacks for dogs and bikes too. So, it's complicated - drop by and see a huge selection of packs and spend some time to try it on, size the harness properly. And if it's for your dog, bring him/her along too!