Whenever I need stuff, I try and look for the really high-quality stuff that'll last me forever, even if it's expensive. But the good stuff is hard to find. What have you bought that has lasted you a long time? Or what's on your to-buy-one-day list?
My most recent purchase is the Peak Design Everyday Backpack. I needed a backpack that could hold and protect all my work tech while also having enough pouches for random small stuff like adaptors and cookies. I totally love this bag - every part of it is and feels well-designed. Top notch build quality as far as I can tell. The side-zippers have turned out to be extremely useful, too, and it manages to fit my laptop, iPad, keyboard and accessories so easily.
edit: I'm also the proud owner of a Herman Miller Aeron. Haven't had it for long but it's great and should last me forever.