I just have a Levi's denim backpack. I didn't buy it for commuting, but it works well and I take it with me everywhere. It has a sleeve in the back (that snugly fits my 13" laptop), another larger compartment, and two smaller compartments (there's a zipper in front covered by front flap I use for fast access to things such as keys or wallet, the other inside for important documents or smaller valuable items.

Amazon.com: Levi's Luggage Genesis 17 Inches Backpack, Grey/Charcoal, One Size: Clothing