Plus five GeekPoints
The statistical software (Stata) that I use at work runs primarily off the command line and/or scripts -- although you can also work with it through the GUI (the drop-down menus).
One of the cool things that I like about Stata is that if you type "exit" into the command-line window, the software shuts down: delightfully old-school. I figured that Linux must have something like that, so I Googled it.
And thus, last night I successfully used the command "sudo shutdown -P now" to turn off my PC (running Mint Linux 17).