I have been using a Camelback Trans Alp backpack for 4 years - awesome pack. I use it for a 1hr commute each way and it is my go to pack for everyday use as well. Fits great, lots of pockets for organizing your gear, helmet & shoe pockets. The only think I would add is a spot to attach a blinky - I'll probably get a tab added myself.

Not cheap, but when this one wears out I'll be buying another ASAP. And I own at least 4 good backpacks - this one is the best by far.

ARRRGGGHHH! - just checked the Camelback website - seems they don't make the Trans Alp anymore - sh*tty. If you see one at you LBS grab it!