May be late to the party, but I love Jansport -- lifetime warranty, no receipt, no questions asked.
I was given a big ol' backpack by a friend, I used it for years, the zipper broke, and I sent it to Jansport. They gave me a brand new deluxe backpack (because the old one was so big). I imagine I will have this backpack (or it's replacements) until the day I die. Then I will pass it on to my daughter. :)