I recently noticed my old IBM Model M keyboard sticking out from under the bed.
Back in 2011 (http://goo.gl/DIhjyZ), I had decided to give it a wash and cleaned not just the removable key-caps, but I also soaked the entire thing in soapy water. It turned out not to be a good idea, as my END key stopped working after that. You don't realize how often you use the END key until it stops working. I tried every form of torture on it I could ... blow dryer, leaving it in the sun, hitting the key with a hammer (ok just kidding) to no avail.
So, sadly, I gave up and bought myself a Unicomp keyboard. Unicomp bought over the rights to the IBM Model M and used the same mechanical buckling spring technology in theirs. It didn't feel quiet the same, but it was close enough.
On a hunch -- three years later -- I plugged in the Model M into my current PC (thank god it still has a PS/2 port) and lo and behold ... the END key is working fine! There must have been some tiny bit of moisture trapped in there for some time.
After all these years, I find feel of the Model M is just that little bit better than the Unicomp, enough that I'm tempted to switch back to it. My F11 keycap is missing but that's probably under the bed somewhere (in the worst case I an pinch one off the Unicomp or look for one online) . More of an issue, is the fact that the Model-M has no Windows key. That didn't use to be a problem until Ubuntu's Unity started using it. It can probably be remapped but it's still change that needs getting used to.
Decisions decisions ...