Redwing boots. Mine are steel-toed. Years of military use, and 35,000 miles of shifting on motorcycles, they're still fantastic. After 10 years, I had to get the soles replaced. That was $106. That brings the 10 year cost to less than $5/month. I was replacing my Bates every few months at $50-100 a pop.
Gerber multitools. I have two. One I keep on the bike, one I keep around the house. A decade of regular use and still going strong. The knives are finally getting a little dull, but I have a wet stone to fix that.
Lodge cast iron. I keep hearing horror stories about newer ones not being nearly as good as vintage, and that cooking eggs is the worst thing ever. At first, eggs would stick, even using extra fat to cook them in. Within a month, that wasn't the case anymore. Now I use the same amount of oil or butter even when I was using what was supposed to be non-stick (and that I've had to use with quality SS-sandwiched copper pans). I cook in my 12" skillet every day. It's the easiest pan to clean I've ever used. Just sucks it takes a good 10 minutes to pre-heat.
Powerblock adjustable dumbbells. These things have been taking a daily beating for 10 years and the soft grips haven't even begun to wear out yet. They cost an arm and a leg, but damn have they been worth every penny. It's having just two dumbbells that I can adjust to fit what I need, instead of needing a whole rack worth.
Ader kettlebell. Another piece of workout equipment that's been taking a beating for a decade. I imagine any cast iron kettlebell will last as long as any other piece of coated cast iron; that is to say just about forever. I mention this because I've seen some very questionable rubber and plastic ones for cheap at Walmart and Ross and the like. Seems more worthwhile to get what you'll know will last, and a pair of gloves if you're worried about grip.
Vacuum insulated stainless steel thermos. Has anyone ever not had one last forever? Because mine seems to be, even if I do keep managing to drop them on rocks and concrete.
I think the general population would be surprised how many things could last a great deal longer than they expect, if they kept up with maintenance. Knives need sharpened and proper care. Fridges, washing machines, coffee makers, etc. all have maintenance cycles, whether they're meant to be BIFL or just making them last as long as possible. Cars aren't the only things we buy that need maintained, but I've rarely met anyone who keeps the coils on the fridge cleaned, or runs vinegar through their coffee pots, or oils their leather furniture/boots/jackets/etc.