Last year, my kid ripped through at least two different rolling backpacks. One of which lasted, I believe, a total of two months. What dreck.
That's why good mommies know to go with LL Bean for backpacks. Sometimes tried and true is simply the best, and even if Bean's retro "Rock Candy Mountain" doesn't resonate with you, the overall quality should. LL Bean backpacks are pretty much impervious to kicking, throwing, banging, overstuffing, and any other indignity your child might subject it to. There's a number of styles and colors to choose from (most kids like the rolling type, although I feel that defeats the purpose of a backpack).
Plus, LL Bean's backpacks are now 20% off. Go and browse, go and buy, and then rejoice, since you won't have to buy another for at least a year. Find them (and get the monogrammed too) at LL Bean.