Did I read wrong or did you call Jansport garbage? Every outdoors pack that I have is a Jansport. I bought them when they were one of the only things in my price range, but still couldn't be happier. My external frame Rainier has been dragged and dropped down sides of cliffs, and other abuses, with no problems. It's carried way more weight than any pack should be expected to carry, and it's done it without breaking or becoming uncomfortable. It distributes weight exactly as a pack should. My other pack is a single compartment top loader, without frame but with strong back padding and a waist belt. Neither pack has so much as a torn seam from years of extremely hard use. No strap has failed, no zipper has failed, no water has leaked in.
I agree, Jansport makes some durable and decent gear. They are definitely not the best designs, but they are very good for the money. Just look at the millions of kids with Jansport backpacks that carry 50 lbs of books at school everyday. I don't know about you, but I am a lot nicer to my gear that a 10 year old is, so I think Jansports can hold up just fine. They have some neat ideas with their internal frame packs, like the detachable parts for wandering away from camp.
I personally use a Gregory Forester at the moment. I am about to switch to an Osprey Atmos 50, since I don't need the 4800 ci that the Forester has. Also, the Atmos's mesh back is friggin cool. Not super durable, but that is what you get for a 3 lb internal frame pack with 3000 ci.
Like someone said before, the whole idea of an internal frame pack is that it takes the weight off your shoulders and puts it close to your back and on your hips. With a good internal frame, you can remove the shoulder and sternum straps when your shoulders are tired, and your 40 lb pack will stay next to your back with just the hip supports with no problem. If you look hard enough, you can find a nice one for under $50, and a really nice one for under $100. My favorite spots are rei.com's outlet, sierratradingpost.com, and backcountryoutlet.com. Steepandcheap.com has them all the time, but they only have one item at a time, so you may have to watch for a while.
As someone else said, go to a store and try the different kinds of packs. You don't necessarily have to take your own gear, but it is a good idea so you can see how to properly pack it. Any outdoor store like REI will have weighted bags for you to test the pack. Walk around the store with it looking at other stuff, so you can see what it feels like. Try the Atmos, so you can see how awesomely comfortable it is.
