I've largely given up on hard sided cases, unless I have something large and that will not cope with bending well [paintings, clocks or large electronics displays - don't ask....] Over the past decade & more of work & holidays all over the northern hemisphere, I've settled on a series of soft duffles. I tend to go for the type that have detachable sholder straps to turn them into a ruicksac and for the larger ones the addition of a couple of wheels to make them drag-able over rougher ground.
I've also favoured different construction for different routes. Where there is a chance of the bags being outside in inclement conditions, I've tended to favour a Scandinavian based manufacturer with matching initials who also do yacht & offshore work clothing. I agree with the advice from Saintsman & Redsnail - avoid black, Luckily they do a range of colours & fabrics. I prefer the barrel type duffel in international orange colour in the vinylised polyester fabric & welded seams. Largely bomb-proof and very robust zippers & padlocking arrangments. For trips where I'm likely to be more on the road than in the air, I've a preference for an american manufacturer named for a generic raptor and small river, Broadly similar to the Scandinavian manufacturer, except they are squarer and come with multiple attachment and tie down points, being designed for use unprotected on a roof rack, they are pretty weather proof as long as you place them sensibly. I tend to use extra coloured luggage straps around them helps to ID them and saves lookiing for something to tie them onto the roof rack if needed.
ZFT has good advice too. I've a couple of Walmart origin 2 wheel expandable cases that I got about 20 years ago for not much money that have done sterling service. Also I'd suggest that you might want to pre-distress your case. If you can put some distinctive marks on it, it makes it easy to pick out at the other end.