Lol, it depends on what you consider "handy" as.

The main purpose of command prompt is to make things faster and easier. I myself prefer to type things out instead of having to click on them.
Some of the common codes that i use?
Spider - opens spider solitare
Notepad - opens notepad
Pinball - opens pinball
Pbrush - paint
Firefox - opens firefox
Taskmgr - opens task manager
-the list is endless
If you want a list of codes, type "Help".
If you want to know more about a specific code, type "/?" after the command.