* My NES is 33 years old this month. I've replaced the 72-pin connector, but that's it. Everything on it could be replaced, so it'll last as long as I want.
* I've a Panasonic flip clock from the very early 1980s. Still works great after carefully refurbishing it. Radio quality is still quite good.
* My father's trains I think he bought in West Germany in the late 1960s. The locomotive is still on its original motor, and may still be when I pass in 50 years.
-----
I'm sure my father's old HP calculators are still working. He bought them in the 70s, but sold them to collectors in tight times in the mid 2000s.