Soft Sided is always my preference, but to each their own.
For soft-sided... if you want a good "budget" brand - TravelPro MaxLite 5. If you want a "Buy it For Life" brand, Briggs & Riley Baseline.
I've been slowly migrating all our checked and carry-on's to Briggs & Riley Baselines over the past year or so, and couldnt be happier.