Each option has it's own merits and minuses.
Stand-by: Uses less power than leaving computer running; however some apps
have adverse reactions when computer is in standby for long periods. Also,
if a power outage occurs while you are away, files and data can become
corrupted.
Hibernate: Uses less power than standby. Some hardware may have problems
initializing when returning from hibernation. Also, Hibernation requires
sufficient empty disk space equal to the amount of RAM installed so that it
may "dump" RAM contents into a file on the HDD.
Turning Computer off: obviously this uses the least electricity of all.
There are those who think that the repeated cycle of turning a computer on
and off shortens the life of the hardware in a computer. They seem to think
that the heating and cooling affect the hardware, and I suppose this is
possible. There are. however, no conclusive studies to support this. If
your computer has sufficient cooling, there is no harm in leaving your
computer on and simply turning off the monitor. Just make sure that you
have a good firewall (both hardware and software), and an up to date
antivirus program running.
Ultimately, it is a personal choice, and there is no completely "right"
or "wrong" answer.
Bobby
