Samsonite Casual Sport!
I posted this a while back in the 9300 forum, it applies to the 9400 as well. I can tell you from personal experience that this is the best laptop bag that I could ever hope to purchase. There is lot of protection and lots of room and pockets to put other stuff. I can put the power adapter in the side pocket, mouse in another side pocket, there's a pocket for CDs, little minifolder divisions for documents, a quick release zipper compartment for fast access to the notebook, and it's very comfortable, even when it's holding 18 pounds. It's also very durable and rugged. i believe the Dell backpack is the same model, except it says DELL instead of samsonite (which i dont like at all). One of the reasons why i got a backpack instead of a normal bag is that it looks more casual and inconspicuous. On campus, it's hard to tell i'm lugging a laptop around - I'm just one of many students lost in the sea of backpacks. The thing with having the DELL logo on the bag is that it screams "STEAL ME".
I'm not saying no one will try to steal your samsonite bag, but I think it does look more subtle. I was able to get mine at Officemax for 40 dollars (with a 10 dollar off coupon). Anyways, this is what I posted in the other thread for 9300s (that fits 9400s):
"This is a great backpack that looks nice, and has so many zippered pockets for organization that it's almost silly. There's a lot of padding for protection as well, and the 9300 fits perfectly. One reason i like the backpack more than a satchel type case, is because i think it looks more 'casual', and thus, less prone to theft.
When you see people lugging around satchel type or briefcase type bags, it's obviously a laptop and you often dont want that kinda attention. I go to college and the backpack just fits right in and melts into the crowd without as much suspicion. I also find it more versatile and able to hold more items, if necessary."
Another nice thing about this bag is that it has a quick access zipper for easy and quick access to the laptop. The rear of the backpack is heavily padded so it's very comfortable against your back and lumbar area.http://www.ebags.com/samsonite/lapto...?modelid=41896
Take a look at the 227 reader reviews about it for more details.