Backpacking adventures give you many options to explore and people have different reasons or ways of travelling. I have been trekking in Central Asia, on adventure travel to Antarctica, on camping tours to the national parks of Africa, on wildlife observation in Alaska, on birding tours to Australia, South East Asia and Latin America and to many other once in a life time travel destinations.
As far as big backpacks go, I think North-face and Katmandu have some really good ones. Certainly a great choice for those after not just a budget case but the best backpack for air travel. While there travelling backpack might be some gray-area on the size of this bag and how many times I'll actually have to pay to check it, the Tortuga Outbreaker is still without a doubt one of the best backpacks on the market.

It all really depends on what kind of electronic devices you will be carrying and what your budget is. If you have very expensive equipment, it is worth it to make the investment in quality travel gear, even if you aren't going to be travelling that far.
If your planning a longer trip and still wanting the convenience of a backpack a good choice may be the the Osprey Farpoint 55 travel backpack One of the advantages of this backpack is the detachable Daypack which can be easily removed and used as a carry on pack.

If you go too big on size for your travel backpack, you'll have a tendency to fill the space and carrying too much gear around the world gets tiring real quick and is not good for the health of your back - we found ourselves de-cluttering and throwing away stuff we didn't need on a constant basis.
Buying a backpack that was meant to be used in the Rockies instead of the streets of New Zealand doesn't matter, though — backpacks are pretty interchangeable these days, and getting a backpack meant for the outdoors simply means you'll have a stronger and more durable pack.

An internal-frame backpack in the 50- to 65-liter range has more than enough room for all the possessions you need to travel anywhere in the world for an indefinite amount of time—as long as you're okay with doing laundry once you get to a destination.
If it's usually a short distance and over fairly well-made ground (e.g. along footpaths), a suitcase with wheels and an extendable handle (to pull it behind you) is best - suitcases allow easier access to clothing, etc, than backpacks and keep clothes less crushed.
Before purchasing my hand luggage backpack or Andy's, I did a fair bit of research as to what was the best carry on travel backpack for us. I read various travel backpack carry on reviews to see what others considered as good backpacks for travelling overseas as well as read up on the best travel backpack brands.

The suspension system on this Kelty travel backpack is ridged, and light, and the straps and back panel are padded and meshed for cooling. Another great thing to look for is a pocket that stores away the backpack straps for transport, so your pack doesn't accidentally break a buckle as it spins around the luggage conveyor belt at the airport.
You can fit everything in this pack and it will remain comfortable and manageable. But there are different kinds of bags for different kinds of travelers. Whether it is a couple of days hiking or an epic adventure The Osprey Aether 85 backpack is the best travel backpack on the market by far.