When leaving a computer, is it better to:

I haven't used the energy saving thing since 1999. I used to have a 24/7 streaming cam using webcam 32 and even though the energy saver wasn't standby it would still manage to crash the cam software.

Nowdays I just turn my monitors off and close the laptop.
Good heat source in winter

24/7 not a good idea i think, screensavers i don't like because they up some resources, expecially very cute once.

the 24/7 problem - as been said before may affect your monitor which i usually turn off manually, the big problem is with harddrives, don't wear out your HD's, with time they become lauder and eventually brake. another thing air flow - you don't want your PC collect dust when it's idle. let the system go off like after 15 min monitor off, after 30 min HD and after 1h whole system.

awake it with mouse or touch of power/reset button, depending on your configuration.

and if you live in the area of constant thunderstorms, powering off might save your equipment. which you already know ;)

standby