In Star Wars Legends and Canon,
Regardless, Vader reported to Tarkin as Tarkin officially outranked him, as designed by the Emperor to limit his power within the Empire.
Many fans declare that Luke won the confrontation because he nearly killed Vader, but that's technically not true. Vader was far more powerful than Luke and easily could have bested him.
Aside from agility and telekinesis, Yoda could absorb and redirect Force attacks, like lightning. Because of his higher understanding, he would easily overcome Darth Vader in a fight, though that doesn't mean it wouldn't be a difficult battle.
In their primes, Yoda would win handily. Though he took the title/name prior to being cut down by Obi Wan, I'll assume the question implies the 'cyborg' Darth Vader (versus the 'fallen' Anakin Skywalker who attacked the Jedi Temple, though in truth, it wouldn't matter much if we compared either version).
In Star Wars Legends and Canon, Galen Marek (Starkiller) is the only Jedi (other than Obi-Wan Kenobi) to put a beat down on Darth Vader/Anakin Skywalker.
1 Darth Sidious
There has been no Sith, as powerful, meticulous, nor as evil as the Emperor himself, Darth Sidious. As previously mentioned, Sidious trained in the Dark Side by Darth Plagueis before Sidious killed Plagueis in his sleep, making Sidious a Sith Master.
Vader used his pain and anger to fuel his Dark Side powers, becoming one of the most powerful Sith ever and perhaps the most feared. He was the enforcer of the Empire, using his red lightsaber and black armor to strike fear into his enemies, becoming an instrument of terror to fight the Rebels.
Adam Warlock is a being of immense power. He has superhuman strength and agility, can manipulate energy beyond comprehension, and has a healing ability that would mean much of Vader's physical attacks would be unsuccessful. This fight would be over pretty quickly, and Warlock would be the victor, no question.
One of the main reasons why Yoda would've won against Anakin is simply because he was far better trained than him. Yoda could see the moves his opponents were going to make before they made them; therefore, battling against Anakin would've put him at a far heavier advantage.
In the process, the Emperor enhanced his apprentice's abilities as he earned back his spot in the Empire. Growing in his power, Vader's confidence that he can kill his master gives him a new perspective. “You can destroy the Emperor.
Vader loses his hate, his anger and thus much of his compensatory connection to the force. So he can't compete against a strong opponent the way he would otherwise in the final fight.
While Obi-Wan Kenobi was frail by the time of Star Wars: A New Hope, he was still stronger with the Force than Darth Vader.
Although Tarkin didn't believe in the Force, he respected Vader a lot, as he was the Emperor's enforcer, and he even grew to admire Vader's way of inducing fear within others.
As Supreme Commander, Darth Vader was the ranking leader of the Imperial Military.
Highly unlikely. Even if Vader is the most powerful user of telekinesis, which he's not, he would not be able to lift up Thor's hammer. The enchantment on Mjolnir will still apply to force powers.
This is an easy one. There's not a person in the Star Wars lore that can beat the Hulk. You could throw every Sith Lord and beings with the force his way and they'd all lose. One by one or all at once, the Hulk would beat them all.
In the end, Thanos' neck is only as strong as his skin. Even if his lightsaber can't cut through Thanos' invulnerable skin, Darth Vader can still Force choke the Mad Titan and prevail.
Luke Skywalker
However, once Luke fully embraced his power in Star Wars: Return of the Jedi, he proved that he was indeed stronger than Darth Vader and struck his father down.
Master Yoda has risen above all others to claim the top spot as the most powerful Jedi of all time and the true chosen one according to IGN's audience. He won pretty handily as well, as he was victorious in 89,756 of his 95,243 battles and had a win percentage of 94.2%.
Truly, the most powerful Sith Lord was Darth Sidious, better known in his public persona of Chancellor (later Emperor) Palpatine. Through cunning and manipulation, Sidious killed his master to claim the mantle of Dark Lord of the Sith.
Darth Sidious, publicly known as Sheev Palpatine from Naboo, became the Dark Lord of The Sith after betraying and murdering his Sith Master Darth Plagueis. Sidious was the Dark Lord of the Sith during the last years of the Republic and the rise of the Galactic Empire.