None of us require much in the way of a knife or multi-tool when backpacking. A small blade will normally cope with most tasks. However greater functionality can be useful on multi-day excursions. The diminutive Leatherman Squirt S4 has been a favourite of Three Points of the Compass across thousands of miles of trail.
The Katadyn BeFree filter has been a favourite piece of gear for the past five years. Unsurprising as it is light, compact, easy to use and has been successful in preventing me from getting sick on trail
Katabatic Gear make some of the best down quilts available. Three Points of the Compass is fortunate enough to own two of their range. They have been used for hundreds of nights while backpacking and each is amongst my favourite pieces of gear. They are superb. I take a look here at the Katabatic Palisade 30°F and the Katabatic Flex 15°F quilts