I'm a fan of the Kata bags. It has a sleeve for your laptop, a padded section for your camera and a good sized pocket for the rest.
I've carried a D90 w/ 18-200, iPad, tripod, cables, extra batteries, etc. through the desert with it. The straps are well-padded, the bag is relatively light considering the padding.
It's not my favorite backpack, per se, for hiking, but it does a good job of humping gear with enough padding to protect it under normal circumstances.
My only complaint is the lack of gear loops or a daisy chain, but that's solved with some creativity and carabiners.