The Lite-Speed is the triathlete of packs: This panel-loader seamlessly transitioned from an overnight in the Adirondacks to a three-day trek in the Tetons, and it's light enough for day trips. An external stuff compartment holds lunch and layers, and oversize side and hipbelt pockets keep smaller items close at hand. The double-stay frame hugs your curves and stabilizes the load, and lets cooling air circulate across your back. 2.3 lbs, 2,600 cu in; golite.com
Bonus: The Compacktor hook system shrinks the pack for light-load days.
Bummer: The top pocket is hard to get into.