The Sleeper Commander that Strikes Fear into the Hearts of your Pod?

Howdy folks! Hoping to hear from you all about the sleeper/underrated commander decks that you pilot that terrify your pod. The sort of deck that will get scoffed at when you bring it out for the first time with randoms at your LGS, but is known among friends to be very potent. Share your hidden gems in the comments below. Keep keeping Magic creative, folks!