I am a full time college student and bought the best backpack EVER at target last month. I was just walking to my car yesterday and I was thinking about how comfortable my backpack was and how it seemed to fit everything. It's a Swiss Army Knife brand-they are a little expensive $40-$60-but are very durable, extremley comfortable, and hold a ton of stuff. It should last you into college. I think they come only in black.
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Target also has cheapy ones, but make sure you try it on, cause some of them cause a lot of backpain when your lugging your stuff around all day
Good luck!