Prime Luke Skywalker
The most powerful known Jedi Force user, surpassing even Yoda in the art. He was capable of similar feats with the Force to Galen Marek, such as ripping down Star Destroyers with the Force. A practitioner of the Light, and even some Dark Side abilities, Luke's mastery of the Force was unparallelled, mastering even the rare Force abilties such as Emerald Lightning. In saber combat, he was one of only three to ever best Darth Sidious in combat, the others being Mace Windu, and Yoda himself, putting Luke within probably the top 5 saber duelists as well. It was stated by George Lucas that Luke was what Anakin should have become before his limbs were replaced by mechanics, the full power of the Chosen One. Luke was the Grandmaster of the New Jedi Order, and was a part of the extremely Force sensitive Skywalker family.
Mace Windu
Master of the Jedi Order, and most likely the greatest Saber duelist of all time, Mace Windu was one of the only people to ever defeat Darth Sidious in combat. Though it's unclear if Sidious were letting him win, or if Mace was actually the superior, it can be easily agreed that Windu was still near him in power. Though he is best known for his skills with a lightsaber, surpassing even people like Darth Maul, and Darth Sidious in the art, he was also extremely potent in the Force, shown in the battle of Dantooine when he defeated an entire army of super battle droids with the Force, and his bare hands alone. Evidently strong in every aspect, some consider him the most powerful Jedi that ever lived due to him being the only Jedi ever to defeat Darth Sidious in the 6 movies.
Two extremely powerful Jedi Masters go head to head! Who wins? The most powerful Force user, or the greatest saber duelist in the series? Don't forget, Luke was also extremely skilled with a lightsaber, just as Mace Windu is extremely potent with the Force. It's definitely a tough match, who wins?!