Short answer — the most durable suitcases usually come from these brands/models (by category), and the most important durability factors are shell material, wheel/handle construction, and warranty:

Top durable picks

• Samsonite Proxis / Winfield / Outline (best overall/value for durability): consistently scores high in lab & real-world tests for tough polycarbonate and strong hardware. (goodhousekeeping.com, travelandleisure.com)
• Rimowa Original (aluminum; premium, extremely tough hardshell): aluminum shells give superior dent resistance and long life if you want a splurge. (goodhousekeeping.com, forbes.com)
• Briggs & Riley (best warranty / long-term ownership): lifetime “Simple as that” repair guarantee makes them a top choice if you want a suitcase you can keep repaired forever. (briggs-riley.com, luggagepros.com)
• Travelpro Platinum Elite (best softside durability / crew‑grade): heavy‑duty ballistic nylon with protective coatings and strong handles — built for frequent travelers. (goodhousekeeping.com, cleverjourney.com)
• Delsey Chatelet Air / Samsonite Omni / Practical budget hardsides: good durability at lower prices — quality polycarbonate or ABS blends with decent hardware. (travelandleisure.com, sfgate.com)

Why these are considered durable (what to look for)

• Shell material: aluminum > polycarbonate > ABS for hardshell durability and dent resistance; polycarbonate is a great balance of impact resistance and light weight. For softside, look for high‑denier ballistic nylon with a water/stain coating. (goodhousekeeping.com, travelandleisure.com)
• Wheels & handle construction: dual/quad spinner bearings and airline‑grade telescoping handles are frequent failure points — higher‑end bags use stronger components and test them extensively. (travelandleisure.com, goodhousekeeping.com)
• Warranty & repair network: a strong warranty (or lifetime repair policy) matters more than a few cosmetic scratches — Briggs & Riley’s lifetime policy is a standout. (briggs-riley.com)

Quick buying guidance

• If you check bags a lot and want “indestructible,” pick an aluminum Rimowa or a well‑built polycarbonate like Samsonite Proxis. (goodhousekeeping.com, travelandleisure.com)
• If you prefer softside and repairs/warranty, choose Briggs & Riley or Travelpro Platinum Elite. (briggs-riley.com, goodhousekeeping.com)
• For best longevity per dollar, Samsonite and Delsey models often hit the sweet spot. (goodhousekeeping.com, travelandleisure.com)

If you want, I can:

• Suggest 3–5 specific models within your budget (carry‑on vs checked), or
• Pull the latest lab test comparisons (drop/wheel/zipper results) for the exact models you’re considering.