The coin, because I can flip every two weeks to attempt total world domination, and it has a pretty high chance of succeeding somehow. Or just more mundane things like flipping to win the jackpot.
The slick talker glasses are also pretty overpowered, you can achieve much the same as with the penny if you can just give a quick speech and everyone in the room either tries to fuck you or be you five minutes later.
But my heart is with the quick sleeper mask, Iβm never really rested after waking up and also procrastinate going to bed all the time. Getting a full rest in one hour sounds like the dream
If you have the coin, you'll pretty much get infinite money. With that you can buy and sleep treatment you need. Also, not having to work means you can sleep whenever you want.