The ballistic nylon management consultant clone (Swanhunter (TM)) Tumi 96041 style. As tough as old boots and is expandable so fits a decent amount of stuff. I can pack for a three day trip and still have room for the electronics. Fits under the seat in front as well.

I went into the store with my mind set on the leather version but I was particularly impressed with the ballistic nylon. Any marks just come right off.

My father has had a Tumi that has gone around 1.5m miles with him and it still looks in pretty good condition. I'm not sure what the style is but it's a leather one and is quite similar to mine.

You can see pics on Google Images or the Tumi website.