I’ve read so much conflicting advice on this–some sources say to shut it down at least once every day because being left on wastes electricity or will wear out components more quickly.
On the other hand, some sources say that shutting it down so frequently can cause just as many problems as all the components heat up and then cool down over and over again, among other problems.
Using Sleep mode is not an option either, since my computer completely spazzes out when I try that method.
For awhile, I was shutting down my home computer every night (usually around 2 AM) and firing it up at about 9:00 the next morning. Now, I shut it down every other night or so. (I always turn off the monitor if I am going to be away for more than a couple of hours, however.)
I suppose I’m on the fence about the issue. 
I turn my computer on and off many times a day, at least half a dozen. Had it a few years and no probs yet, touch wood. I dont like to think of it sitting there consuming power, for no purpose, so I always switch it off when I’m done.
The computers at the company I co-own stay on all the time (NT machines & a couple of old WFWG machines) - they go months, or even years, between reboots. At work, I shut down the W2000P machine every day because I have a failing HDD fan - before that problem I left it running. At home I have an old W95 machine that is breaking down but is left on 24/7 - it needs a reboot ~every 3 days.
i used to shut down every night. but lately i guess i’ve gotten lazy. i try to see how long my connection will last. got up to nine days straight. not bad for dialup.
When my wifes family comes over the house. Otherwise it stays on.
The only time we turn our PCs off is if we’re going out of town or if there’s one of those tremendous Texas lightning storms going on. Then we unplug them, too. I do keep a watch on the fans to make sure they’re running, several home fires have been reported in this area due to fans going bad. I turn my laptop off whenever I’m not using it, but that’s because laptops burn so hot and because it’s usually ready to get packed up without me having to turn it off, etc.
We turn ours off daily. The monitor is what eats the most power but I don’t like to hear it at night.
I turn my computer off whenever I’m going to be gone for more than a couple hours, and every night as well. I imagine I’ll be ready to upgrade before any wear-and-tear from this practice catches up to me.
Every couple hours at the most cuz that’s how often I have to reboot this worthless piece of ****.
Mine stays on pretty much all of the time.
Haj
Mine stays on all the time. It reboots after Windows Updates. The moniter sleeps at night.
When I go on vacation, or when I have people sleeping in the same room. That’s it.
I do put it in Sleep mode most of the time though.
I turn mine off for good at night and turn it on again in the morning. It’s such a power hog, I’d hate to waste eight hours powering it. And I’ve been turning comps off for years without a problem, I’d think by the time they set in, the rig would’ve been replaced anyway.
I turn mine off maybe once or twice a week, usually if I don’t expect to be using it for day or more. On or off doesn’t seem to affect the energy bill, though, so I guess my iMac is a sound sleeper, so to speak. No real problems either way, incidentally.
My eMachine is so dang noisy I turn it off every night and put it on standby every chance I get.
I reboot once a week. The damned thing hasn’t really been turned off for 5 or 6 months.
I leave mine on all the time, unless I’m out of town, or my room is particularly hot at night. Weird behavior meanss a reboot every day or two, however.
Helps me keep in touch with friends in other time zones via AIM, and it also plays music while I’m falling asleep.
My work development machine is always on. My work server machine hasn’t been turned off or restarted in over a month (maybe 2 or 3) (it also doesn’t get much heavy use). My home laptop is on when I’m using it. Otherwise it hibernates. My home desktop is on only when I’m using it because it is very loud (I can hear it from anywhere in my apt.
My Windows (98SE) boxes are supposed to be shut off every night. However, I’m not the primary user of those boxes, just the family admin. Our Macs are rarely shut off, but they are frequently sleeped. I’ve never had a problem waking a sleeping Mac (unless the battery was really low), but I wish I had a dollar for every time one of the Windows boxes just won’t wake up. Perhaps later versions of the OS would be better, but I don’t want to pay Microsoft for the priveledge of having a less buggy operating system. (Now if I could only train the guy who uses the Windows boxes to actually turn off the monitors when he’s done using them…)
JOhn.
Every once in a while. The G4 goes to sleep when I’m not using it. I have an LCD monitor that doesn’t use much power to begin with (so I’m told) and I turn it off when I’m not using it.