Better to leave computer on or not?

[VPR3]

Better to turn it off. HDD life and internal components aren't going to be affected by turning it on and off unless it's a goal to try and tear things up. If components were as fragile as you make them to be, parts makers would be in loads of trouble.

[tremor77]

The consumption/conservation of energy is probably one of our generations biggest social and technological challenges... if everyone took a moment and thought to just turn off one or two additional power consuming devices for even a little while... for the sake of the future of all mankind, shut 'em down.

[rajival]

Let's just put it this way, if you don't need to leave it ON then turn it off. Even machines need to rest. You wouldn't want to protect your hard disk and end up burning your cpu because of excessive heat.