To turn off or not to turn off

What do you do with your PC when it's time for nighty-night?  Some think that using the startup and shutdown processes creates wear and tear so they leave it on.  Others don't want to waste energy. How about sleep mode?  According to Ioto Labs, as reported by Rick Broida at PCWorld they found putting your PC to sleep instead of letting it run saves about $24.00 a year and 25 minutes a month in time for startup and shutdown.  They didn't study hibernate mode. Saving money and avoiding slow boot times is a good thing.