If you're thinking of hiking a long stretch (maybe even the whole) of your local trail, then you're definitely going to need the backpack that does the business. These backpacks are designed to carry everything you need if you plan to be away from the creature comforts of home for a week or more and have more compartments than you can shake a stick at.
Osprey Packs Aether 70 Pack 013070
Gregory Mt. Products Baltoro 75 Backpack GM57911
Deuter Women's ACT Lite 60+10 SL Backpack 434001
Deuter ACT Lite 65+10 Backpack 434011
Gregory Mt. Products Womens Deva 70 Backpack GM59695
Deuter Women's ACT Lite 70+10 SL Backpack 434021
Gregory Mt. Products Women's Deva 60 Backpack GM58031