Travelpro is what I always saw flight attendants and such using when I flew regularly for work. At one point I got a companion pass from southwest in 6 months (100 round trip flights).

Honestly though, most airlines have a luggage department at most airports, if your bag is damaged they will give you a voucher for one, and you can often pick a replacement up at the airport or elect to pick one online and have it shipped to you.

I always used Samsonite with good results. I was a traveling electrician and my 30" bag was loaded to the limit (50lbs) with electrical material for every flight I made, and it never had a hiccup. It was damaged 3 separate times, shell was cracked, one of the corners got a dent in it. In fact I claimed damaged 3 separate times on that 30" bag and have got 3 replacement bags for it. Was never damaged beyond use, so kept using it.

Also you could just replace them on a schedule.