Appears In: Star Wars: The Phantom Menace, Star Wars: Attack of the Clones, Star Wars: Revenge of the Sith, Star Wars: The Clone Wars, Star Wars: Rebels, Star Wars: A New Hope, Star Wars: The Empire Strikes Back, Star Wars: Return of the Jedi, Star Wars: The Rise of Skywalker
The one that towers above all the others and the villain of the entire Skywalker Saga, Darth Sidious was unparalleled in his strength in the Force, talents with a lightsaber, and skills with manipulation.
He was able to orchestrate the Clone Wars, secretly controlled both sides, and successfully created the first Galactic (essentially Sith) Empire in generations. Not only was he able to accomplish this, but he also managed to keep his plan hidden from the Jedi the entire time. It wasn't until Anakin Skywalker discovered his true identity that things nearly came unraveled, but by then, it was too late.
The rule of the Galactic Empire started and ended with Palpatine brutally controlling everything and did not possess an ounce of humanity or compassion for those living under his direction. Palpatine's only goal was to achieve more power and, through that, immortality.
Through the years, his abilities became so strong that he could not only generate Force Lightning but use it to destroy entire fleets, as seen in Rise of Skywalker. His power also grew to such a point that, as he alluded to in Revenge of the Sith, he was able to cheat death.
When Darth Vader threw his body into the Death Star reactor, he could transfer his consciousness into a clone body on Exegol, a planet across the galaxy. From there, he used his scheming skills again, orchestrating the rise of the First Order, the creation of Supreme Leader Snoke as a puppet, and the Final Order, nearly conquering the galaxy again.
His power was seemingly incalculable, and if he were to face off against any other Sith Lord, he would likely defeat them with ease.