longest - Army wool jumper. it was issued to me used so I guess at least 10 others wore it before me, and I had it for almost 20 years until my car was stolen - with the jumper in the boot. Also: Army boots.Again issued not second hand but probably tenth hand. I had them now for the same 20 years, resoled a handful of times, still going strong, use them in average two days in week for all kinds of work and bush walking. Of the non-issued stuff Asics trail running shoes seem to take more than their competitors. I had a couple of pairs for five to seven years (I admit with the help of some super glue) Berghaus backpacks have lasted me twice as long as others at half the price. Got two Carinthia sleeping bags. Man they were expensive but I got one for 14 years and the other one for 19 years now. Whilst their insulation has suffered a bit over the years they are still doing the job, and I use them A LOT!
Shortest - pair of Nike trail running shoes. Two weekends and they were completely wrecked. Paid AUD 200 for them so would have expected to get at least a few months out of them. Unfortunately I agree with Robson valley on Columbia. Never got my money's worth. Looks the part but doesn't last. I guess it's designed for the summer vacation warrior that uses his gear once a year and still gets his three to four seasons worth.