I used a super-tough commuting backpack, hand made in California by Inside Line Equipment, for a full year through way more use than most people put their bags through. Bike tours, blizzards, crashes, deserts, months of travel and, of course, my daily commute.
Here's my review!
Do you guys use backpacks or saddle-bags? Got a preference?
I don't have any affiliation with the company, and I paid full price for the bag, just FYI!