If you are on a tight budget, this Rebecca Minkoff Backpack will fit the bill. It's a great choice, while not very expensive. In this price range, you can also take a look at this Rucksack. It's also a popular item and won't break the bank. You may also want to look at this Backpack. This item is not expensive either, but it will make a difference in your wardrobe.
If you want to splurge, then you absolutely must check out this Stella McCartney Backpack. This item seems costly, but it's well worth it. While you're at it, also have a look at this Fendi Backpack. Yes, this item is expensive, but it does not mean it's not worth it. And one more item you might be interested in is this Gucci Backpack. 'Cause you deserve nothing but all the finer things!