Galaxy's Best Emperor Mugs were a specific type of present manufactured during the Galactic Empire's era of rule. These mugs came in two colors: white and red. They bore the phrase "Galaxy's Best Emperor," which was intended as praise for the Galactic Emperor, specifically Sheev Palpatine, also known as the Emperor, along with his likeness. However, Palpatine himself was not pleased with these mugs, viewing the adulation as meaningless since he was the only Emperor in the galaxy.
Galaxy's Best Emperor Mugs were cylindrical containers designed to be held in the hand, each equipped with a handle. These mugs were decorated with an image of the Galactic Emperor, Sheev Palpatine, and the inscription "Galaxy's Best Emperor" in the Aurebesh alphabet, celebrating Palpatine's reign over the Galactic Empire. One version was red, featuring the text across Palpatine's chest in his zeyd-cloth robes. The white version showcased a headshot of the Emperor, surrounded by the "Galaxy's Best Emperor" inscription.
At some point between 0 ABY and 4 ABY, Palpatine threw a party for his Imperial officers aboard the second Death Star battle station on the night prior to Life Day, an important annual celebration. Within his throne room, the Emperor offered gifts to his subordinates but insisted on a white bantha swap – a practice of stealing gifts from one another – to instill a sense of competition, in accordance with Sith principles. Joining the ensuing commotion himself, Palpatine seized the gift of his Sith apprentice, Darth Vader: a white Galaxy's Best Emperor Mug.
As the Sith Lords fought over the mug, R2-D2 – a rebel astromech droid who had infiltrated the Death Star – was appalled by their behavior and snatched the mug. The droid managed to avoid the Imperials who pursued him on the Emperor's orders and reached his T-65B X-wing starfighter to escape the space station, but not before launching the mug down the station's exhaust port. Vader later recovered the mug and returned it to his Master, which infuriated the Emperor upon discovering it was broken.
Around 3–4 ABY, Vader gifted Palpatine with a red Galaxy's Best Emperor Mug for Empire Day, a holiday that celebrated the foundation of the Empire and honored the Emperor's greatness. However, Palpatine was unhappy with his apprentice's gift, finding the title of "best Emperor" redundant as he was the only one. He gave the mug to his Royal Guard instead and sent Vader on an off-world mission. The Sith Master's displeasure continued when the same guard tried to return the mug, leading the Emperor to smash it. After ensuring no one was watching, the Royal Guard quietly swept the broken pieces under the Emperor's desk with their foot. Shortly after, an Imperial officer presented Palpatine with another Galaxy's Best Emperor Mug, to which he responded by asking if the item was on sale.
Later, Vader visited gift shops on the Outer Rim planet of Batuu and purchased a white Galaxy's Best Emperor Mug for Palpatine as a Life Day gift in 4 ABY. He presented the gift to his Master in the latter's throne room aboard the second Death Star, unaware that they were being observed by Jedi Master Rey Skywalker and the astromech droid BB-8 from afar. Rey and BB-8 had traveled from the future using a key that could open Force gateways through time and space. Once again unimpressed by the mug, the Emperor threw it aside, causing it to bounce off the droid and alerting the Sith Lords to the presence of the watchers. Intrigued by the open portal left by Skywalker and BB-8, the Sith Master threw the mug through the gateway, prompting Vader to complain about his efforts in finding the gift on Batuu. Palpatine then tasked his apprentice with finding the source of that power and threw him into the portal as well, which led Vader to a Jedi Temple on Kordoku. The Dark Lord eventually completed his task by bringing the key back to his Emperor, also retrieving the Galaxy's Best Emperor Mug that was lying on the temple's floor in the process.