For a unique answer, I’m going to say my model trains from the 1940s & 50s (Lionel, O gauge). They were designed to be taken apart & serviced, and it shows. And they have enough common parts that even though they’re now 75+ years old, you can still get parts.
I’ll also throw my 1997 Ford F-150 into the mix as a more common answer. Ford made literal millions of these, so not only are parts still available, they will be for decades still to come. Heck, I replaced the motor last year, and was able to get most of the bolt on parts I wanted straight from the dealership. Not bad for 25+ years old.


Probably doesn’t count as I didn’t buy it, so I’m technically not dealing with it. But let’s talk about electric riding lawnmowers. Last year I was looking to replace my 20+ year old riding lawnmower with an electric one. Could not find a single manufacturer who would also provide the parts lists. Digging deeper, seems like they simply do not sell parts, like at all. The mowers just aren’t repairable - straight up, if it breaks, buy a new one. That’s irresponsible when talking about an electric drill, but a full riding mower? WTF?
To be fair, this might be a chicken & egg problem. Low adoption rates means there’s a very small market for parts, so there’s no aftermarket support. And that aftermarket is where I get parts for my current mower. So maybe it’s not fair to blame the manufacturer? But I think that’s a stretch. From where I’m standing, it sure looks like intentional planned obsolescence.