I can still remember the minute I shut mine down. I don't remember all the details of what prompted it, but just a few days shy of the board's 10th anniversary, I got up from my desk and started shutting down computers (12 of them) and then the fileserver. Didn't even "down" it. Just turned off the switch.
Then I sat there, both bummed and relieved (kinda like when I was laid off from SI, actually), and savored the first time in years I didn't have the noise of computer fans and hard drives going on in the background.
Then I remembered that the BBS boxes weren't the only machines that needed the fileserver, so I finally got up and turned it back on. <g>