Hmm. Probably made loads of bad investments, i simply have chosen to forget about them
First thing that comes to mind is a backpack. Häglöfs shosho. Brilliant frontloading pack.....with 3 kg worth of zippers. Soon got changed out though.
MSR gas-lantern. The one with the metalmesh instead of glas. Produces great working light, is fairly lightweight, fairly noisefree during operation, and can stand up to almost any abuse. But lets face it. Whos going to carry the alntern aswell as 1 or 2 gasflasks around for a 2 week hike?
Knife-ways i still use and carry the very first knife i ever made. Scandinavian style, good ole danish oak, black horn, and a 8 cm blade made out of the coilspring out of a beemer. Honestly it is the only knife i ever use. (but i too must admit to have huge amounts of knifes lying around wich i never use. Most of wich are Mora og the like)
Clothing. I have the Härkila Lappland set. Jacket was bought first. A few years after the trousers came along. Expensive as h..., heavy, robust, and Goretex. Never had any trouble with it. In fact if i pull the legs of the pants tight enough to my boots i can walk across streams without worrying about water in my shoes. Done so quite a few times now.
And the i have variuous amounts of wool and cotton shirts, turtlenecks (from the army) Pinewood lined pants and what not. (basically the cheaper alternatives.)
Worst buy of it all: the washingmachine from hell, that managed to boilclean most of my woolen clothing last year :Thinkingo