I've never owned a traditional suitcase in my life. I've always had the modern "pilot's case" style, with wheels and extendable handles. They're what I like to call "semi-soft", since they're made of cordura but have plastic liners to give the sides some stiffness. They're not as strong as an actual hard suitcase, but they're about 1/4 the weight, and the modern wheels and handle make them a lot easier to manage when travelling.
But my current luggage is all American Tourister. I have a large blue one that's my checked bag. I got it at
WalMart several years ago, and it holds everything I need for an extended WDW vacation with ease, though I have to be careful not to overpack on my way home and incur those overweight luggage fees. Being soft-sided, it will deform a little when other stuff is stacked on it in the luggage compartment of a plane, but so far nothing has ever broken. For safety's sake I always add a strap around the outside to keep the lid closed in the event of a zipper malfunction.
Last year I bought a smaller mobile office case from Walmart, and turned into a camera/laptop bag by making custom foam inserts for it. It's now my carry-on. It's no Pelican, but the foam insert I made has custom cut-outs for all of my camera gear, keeping it all very protected when inconsiderate louts shove it around in the overhead to get their own over-sized junk up there. And it doesn't look like a camera or laptop case, either, so my hope is that it will be less of a target for luggage theives.
I like the American Tourister brand. They're built pretty tough, but they're cheaper and easier to find than Samsonite.