Updated June 16th, 2019.
If your keyboard has an Eject key you can bring up the Sleep/Restart/Shutdown dialog by pressing Control and Eject together. Here’s how it looks.
No need to go to the Apple menu to do it. Just Control-Eject. Of course, if you’re using a laptop you can probably just reach over and press the power button on the keyboard, but this may be easier. And of course on an iMac the power switch is in the back, so this is the faster way.
This shortcut was discovered with the help of Charlie the Cat, who was pressing down on the Control key while I tried to eject a disk from the keyboard.