I have been using Tumi luggage. It is soft-sided, but those soft-sides are built of ballistic nylon. My Tumi luggage shows a lot of wear, but it has yet to fail me.
I just purchased a Hardigg im2500. This hard-sided case is manufactured with injection-molded plastic. It’s also waterproof. This case will protect itself and whatever you put in it.
Very conveniently, the case is the maximum size allowed by FAA regulations for carry-on use. This is the toughest carry-on that you will ever own.
Hardigg doesn’t sell to end-users, so you will have to go through a reseller to purchase this case. I tried to purchase one of these a few months ago and the reseller never shipped it. Luckily, I found a good reseller this time, John at Deployable Systems. John saved me a lot of money on this case, as he sells it for only $109.
The only downside to the case is it’s carrying capacity. Due to the design, it is noticeably smaller inside than my Tumi carry-on. With this case, you will have to pack lighter than usual — but what you pack will get there safely.