I've got a Lowepro Computrekker AW (backpack style bag with a laptop sleeve). I doesn't look like they make that one anymore but I'd guess it's pretty similar to the Pro Runner AW listed above.
I've toted that bag around the world and back, over the last 10 years. It's certainly not perfect but it's well made and still looks and works great.
In the Lowepro lineup, the 'AW' stands for 'All Weather' and they come with a built in rain cover. I've only had to use it a few times, but it's a nice feature if you plan on being outdoors a lot.