Saruman is hands-down the best villain. Allmost the other villains are great and powerful and... distant. They wield their power on a huge scale, with armies of thralls, corrupting the very lands that they inhabit.
Hurin. Hurin was an amazing warrior among men during the First Age, and was instrumental in many of the battles around this time. Said to have incredible skills in both forging and wielding weapons, he was a valiant soldier who unfortunately twisted into terrible things by Morgoth by the end of his life.
Who is the overarching antagonist of Lord of the Rings?
Mairon, better known as Sauron after his betrayal of the Valar, is the main antagonist of J.R.R. Tolkien's Middle-earth legendarium. Once the greatest smith in service to Aulë, he joined with the first Dark Lord Morgoth during the First Age, becoming his first lieutenant.
Defeated by the Host of Valinor in the War of Wrath, Morgoth was banished from Middle-earth into the Timeless Void, though it was prophesied that he would one day return.
Eru is introduced in The Silmarillion as the supreme being of the universe, creator of all existence, including the world, Arda, and its central continent, Middle-earth. In Tolkien's invented Elvish language Quenya, Eru means "The One", or "He that is Alone" and Ilúvatar signifies "Allfather".
Ancalagon the Black (Sindarin: rushing jaws from anc "jaw", and alag "impetuous") was a dragon bred by Morgoth during the First Age, as told in The Silmarillion. He was one of Morgoth's most powerful servants, the mightiest of all dragons, and the first of the winged "fire-drakes".
Ultimately, the only being more powerful than Morgoth in his prime was Eru Ilúvatar. Only the combined effort of the Valar could stop Morgoth, and only after countless battles. Sauron might have bested his mentor under certain circumstances, but Morgoth is the greater Dark Lord by every metric.
Eventually, Morgoth was bound in chains by the Valar and thrown into the Void, leaving the permanent damage his evils had done, and his former lieutenant Sauron, to trouble the world. One day, according to a prophecy, Morgoth will rise again in great wrath, but he will be destroyed in the Dagor Dagorath.
In fact, Sauron during the Second Age was more powerful than Morgoth at the end of the First Age. Here's a quote from Christopher Tolkien's Morgoth's Ring that offers an extended explanation: "Sauron was 'greater', effectively, in the Second Age than Morgoth at the end of the First.
Smaug's dragon-fine would not have been hot enough to destroy the One Ring. The malevolence that Sauron put inside of the Ring could only be destroyed in the Cracks of Doom, so Frodo was compelled to make the journey to Mordor.
The Dwarves weren't immortal like the Elves, but they were still formidable fighters. Some fans would point to Durin the Deathless or Azaghal as the best-fighting Dwarf. However, the strongest Dwarf was actually Dain Ironfoot, even if he wasn't the sharpest axe in the armory.
All that is gold does not glitter, not all those who wander are lost; the old that is strong does not wither, deep roots are not reached by the frost. Not all those who wander are lost. All we have to decide is what to do with the time that is given us.
Originally known as Melkor, Morgoth is essentially the Lucifer of Tolkien's story. Like the devil, Morgoth was one of the first children created by the God of Tolkien's world, but succumbed to jealousy and greed, especially over the creation of other races, and was duly disowned by his fellow Valar.
Aragorn. Aragorn might just be a mere mortal man, but he is certainly an incredibly gifted one. With a heightened sense that helps him track things greater than any character in Lord of the Rings, Aragorn is incredibly smart.
As previously stated, Gandalf is a Maia and is therefore superior to Elves regarding power. Still, this isn't to say that an elf couldn't develop enough skill and power to defeat a Maia. As a bearer of one of the Three Elven Rings (Nenya), Galadriel would have an edge against Maiar like Saruman and Radagast.
The majority of her powers come from her Ring of Power, Nenya, the Ring of Water. The ring, also known by the names the White Ring and the Ring of Adamant, is one of the three Rings of Power given to the Elves of Middle-earth in the Second Age.
If we are talking only about The Lord of the Rings I'd go for Glorfindel among the male Elves, as many have already answered. For the female Elves it's difficult, because Galadriel is described several times as very beautiful, but about Arwen it is said that “the likeness of Lúthien had come on earth again”¹.
In The Lord of the Rings, it is said that had Galadriel chosen to use her powers for evil instead of good, she would have been even more destructive and terrifying than Sauron himself. Galadriel was the greatest and most powerful of all Elves in Middle Earth in the Third Age.
However, near the end, Morgoth had dispersed so much of his own power into the world, that (Tolkien wrote in a private letter) he was actually weaker than Sauron. Sauron made torture a specialty. Morgoth tortured people too, but Sauron was really into it.
For that matter, the Valar didn't have the authority to remove another Ainur's power. If they had had that authority, they would have stripped Morgoth of his power, rather than going to war with him so many times.
"So I think in his pitch to Galadriel, it cannot mean that he loves her or that there's any kind of romantic relationship. There should be no ambiguity around the fact that Sauron is evil — he's terrible, and he's using Galadriel to enhance his power."
