When we first started traveling, we almost exclusively used backpacking backpacks. Designed to comfortably carry a lot of weight on your back, or rather your hips, these bags are great for overnight hiking and camping trips.
However, these bags are also convenient when moving from place to place where there are a lot of stairs. We found them invaluable in rural Asia and South America where sidewalks are mostly dirt and wheeled suitcases get destroyed.
Comfort is key when picking a backpacking backpack. Instead of buying them online, support a brick-and-mortar outdoors store who can help pick one sized for you. Load it up with weight and try it on. Wear it around the store while you shop. Seriously, it’s the only way you’ll know it’s the right bag for you.
We’ve always had good luck with the brands Osprey and Deuter. However, if you’re looking for something less expensive, many backpacking friends have found good deals at military surplus stores.