@futurebird There are so so many.
I have a little adapter cables for pretty much every connector ever put on a cell phone. Including some that are USB on one end and the other end is shaped like the phone battery.
Worst that I've made and still regularly use: NEMA 14 (US dryer plug) to NEMA 5 (US wall outlet). Yes it is wired to provide 220V to whatever you plug in.
A cable that has been in the box of USB cables for over a decade but I've literally never used:
