I have the Jansport Firewire.http://www.ebags.com/jansport/firewi...?modelid=20165
Awesome bag as it offered the most padding out of all the bags I've looked at. I've looked at all the ones offered at Bestbuy, Circuit City, and compared specs on all the bags on eBags, so I've looked through hundreds of bags.
This bag will fit your laptop, adapter, notebook cooler, ext. HD, mouse, headphones, calculator, PDA, 3-4 books, couple spiral notebooks, your wallet, and a bottle of water. How do I know? Because, I've had all these things in my backpack at ONE TIME!
How many bags out there can claim that it can fit that much stuff and still not feel heavy (airlift system) or offer 2in of padding (shockshield) for the bottom of the laptop? Very few and none in this price range (Jansport Exos System ~$170, not available at the moment, and Bolbee bags ~$150-$200).
Hopes this helps your search.