I usually use Hibernate in Windows 7 since waking from hibernate only takes a few seconds.
Standby is kind of annoying since the lights on my computer still blink on and off. Plus, Sleep mode is still powering the Memory/RAM, so it is still using a little bit of power.
I usually use Shutdown when I am going to bed since I don't plan to use my PC until I wake up in the morning.
In Ubuntu, I use Shutdown since I rarely use Ubuntu, so I don't really care about the boot times. Plus, Ubuntu boot time is pretty quick.
If I am going to be away from the computer more then a hour or two I will shut it down. I use to Hibernate with my old computer but after I got my new one it didn't have the option so I looked into getting but soon learn hibernate can slowly ruin your computer. So I highly recommend not using it.
I just heard Hibernation can slow down your PC if you did not shutdown or restart your computer in a long time like a few months since by restarting your PC your files are reloaded and all the old files in the RAM is flushed out.
I read many computer books, forums, and watch computer videos which said hibernation just uses a little space on your hard drive to save a copy of your memory's/ram's content before turning your system off and then reloads the ram's content from the hibernation file when your PC is turned back on.
