As an airline employee, we get TravelPro. I think it is really one of the best. I have dragged it around for twenty years. It does need replaced every now and then. It is lightweight, reasonably durable, and has all the features that a road warrior would want.
On a recent trip to my local luggage repair person (to replace my wheels on a 5 year old TravelPro) he suggested buying a new Hartmans. He said it is the best there is. I thought it was pretty sharp but it is expensive.
As I watch a lot of our First Class customers board, I see a lot of Tumi. I have no experience with it but it seems pretty popular.