I love Toughskins at Sears! I've exchanged 3 pairs this school year after my sons put holes in the knees. Absolutely no questions asked, no receipt needed, and brand new jeans! The ones I got were cute, too, not the super basic ones and on sale about $12.
There is a 15% off friends and family event through tomorrow morning on Sears.com, I was just going to go look for a couple more pairs!
By the way, is Canyon River a Sears-only brand, too? I know they will honor all the brands they sell, but if it isn't exclusively theirs, you need the receipt. I don't want to bother with that!