My Amstrad PC 1512 (bought sometime in 91 or 92) still works. Or at least it did an year ago when I was doing some cleanup on the attic. I didn't plug it into a monitor, but could hear the disk operating normally and the computer seemingly booting into DOS. It's keyboard still works too. I blind typed "dir" and I could hear the disk starting.
My Toshiba Satellite Pro 6000 (bought in 2001) still works flawlessly even despite one visit to support around 2004. Its keyboard is another matter. 'A' and spacebar keys are gone (physically gone) and a group of keys on the right side ceased to operate. Works perfectly attached to an external keyboard.
This laptop, despite being a decade younger is a much more notable case than the Amstrad above. It traveled with me a bit all around the world for 5 years. It experienced sub-zero temperatures in Canada on a basement, desert temperatures in Alice Springs, Australia on the dead of summer. It also witnessed hot humid temperatures in Singapore and has fell to the floor from waist high at least twice that I can remember.
Impressive? Not really. Wait until Tharic-Nar replies to this thread
He has an amazing collection of old stuff he kept through the years. Some of which, I'm sure still work.