I have a speck aftpack
http://www.speckproducts.com/products/aftpack-backpack/notebooks-up-to-17/170
I really enjoy it. I've been using it 2 years strong and it still looks brand new. It's just a bit more stylish (if that's your thing).
There is considerable padding for a notebook, it is also firm and resistant to bending. It has a zipper on the other side to access the notebook without having to fumble through other books and it is very convenient.
The main pocket is very roomy. I fit 3 textbooks, 1 being a large calculus book, 3 1in binders, an extra notebook, and a pack of flash cards. There is another decent sized compartment in the front with room for small notebooks, pens, pencils, etc. It's VERY large for a second compartment.
I carry my TI-89 graphing calculator, Magic mouse, planner, hoards of writing utensils, stapler, instant coffees, candies, etc. cell phone, keys, a novel to read, and a boogie board. I still have enough space for a few more things if I needed them.
Also, when the bag has a book or two in it, and the notebook, the rubber feet help the bag stand up on its own making retrieval of things very easy.
It is also just comfortable. I got the bag half off at a local store but coupons are always floating around the internet. I'd definitely give it a try.