I like the one where you can hit "shift" five times in a row and Windows will prompt you to if you want to turn Sticky Keys on, which I never do.
The one I use the most is good old Alt-Tab, or WinKey-Tab for showing off. Alt-D seems to be the one which is most like witchcraft for people who don't know it.
EDITED: 29 Jan 2020 10:40 by WINGNUTKJ