I think my favorite key on any keyboard is the "Fn" key. Why? It's the F--in key! You can curse at someone whenever you talk about it, and they won't be sure if you're actually cursing at them.
"Click the icon, then hold down the f---in key, and press 'P'".
I wish they would just re-work the letters on it so it was officially the "f---in" key.