The right answer of this question can depends on how much you used your own computer systems. My recommendation for the most likely users is that when the system is first turned On that is remains On until is is late, or you want or think that is is not used further. However, if you want tasks yo run during the night time, like as a Backup, ScanDisk, De-fragment, or Scanning , you will have to leave out the computer system On overnight.
My Tip : If you want to keep your computer systems On because it takes the very long time to for Booting, after it has been Off putting your system into Standby or putting your system in Hybernate instead turning the computer Off.
It is neither good nor bad to turning the system Off each day or for you to leave your systems on all day every single day.
My Tip : If you want to leave your system On all over the day, then i recommended you to Off the LCD or Monitor. Even also if you stepping out from the system for more than 10 to 15 minutes then also turning off the LCD or Monitor.