The best Star Wars lightsaber fighters are almost unbeatable in combat. Even a non-Jedi can use a lightsaber, because it doesn't require the Force to switch it on; but the best lightsaber duelings are always Force-sensitives, simply because a Jedi or a Sith is able to bond with the kyber crystal within their blade through the Force. Using a lightsaber is less like fencing than it is directing a current of power, making the best lightsaber duelists true forces to be reckoned with.
There are currently seven different lightsaber forms in Star Wars canon, and each form specialized in an aspect of conflict. While Makashi (Form II) was known for its graceful and careful strikes but it lacked the nimble acrobatics of Ataru (Form IV). Most of the best lightsaber fighters studied or dabbled in all seven forms, though some specialized in a specific form or created hybrid forms by combining multiple styles at once. By having a strong understanding of every form, the best lightsaber fighters were able to quickly switch their stances mid-combat in order to suit the situation.
10 Rey 
Daisy Ridley's Rey initially waved around Luke Skywalker's lightsaber as if it were a toy, but she ended up training to become one of the most formidable lightsaber fighters in the sequel era. According to Jason Fry's novelization of Star Wars: The Last Jedi, she absorbed some of Kylo Ren's knowledge through what was later revealed to be the Force Dyad; "It was as if his training had become hers, unlocking and flinging open door after door in her mind." She was then trained by both Luke Skywalker and Leia Organa. Additionally, by studying the sacred Jedi texts, Rey was able to get a unique overview of the lightsaber forms through lightsaber diagrams. By the end of the sequels, Rey’s skill with a lightsaber allowed her to reflect Palpatine’s deadliest lightning bolts back at him.
