Who is the Hero of LOTR?
Just as a fun side-bar, who do you think is the "true" hero of LotR? — Real Gone Cat
I haven't read Tolkien's letters, so I have only the text to go on. I would choose Frodo as the hero, for the reasons that Frodo:
Was an ordinary person--very strong, good, honest, etc. but was no super-hobbit.
Did not seek out the ring.
Did not perform selfish, evil acts with the ring while he possessed it
Found the ring very burdensome
Did not have any supernatural powers (such as simultaneously existing in Middle Earth and the Undying Lands at the same time, or lived an extremely long time, if not forever, or had magical powers like the wizards.
Suffered grievously for the role he fulfilled
Sam was cut from the same extra fine cloth as Frodo, and while he bore the ring briefly, he didn't sacrifice as much.
Aragorn, Tom Bombadil, Elrond, Galadriel, various of the Elves, Ents, hobbits and Rohirrim, various Men of the West associated with Minas Tirith, dwarves, etc. -- all had their significant virtues. But some couldn't be heroes because they had supernatural powers: Tom, Elrond, Galadriel, or elves.
I would rate Aragorn (Strider) as the first runner-up hero. Arwen merits a special mention, since she gave up immortality to stay in Middle Earth with Aragorn, whom she married.
But it is Frodo who bore the wounds inflicted by, or on behalf of the Ring. Bilbo also suffered, but more with advanced Ring-associated befuddlement, rather than agony.
Frodo is the Christ figure, willing to sacrifice himself to take away the undying threat to Middle Earth. Even if he stumbled at the last moment and claimed the ring, (shortly to lose it when Gollum bit off his ring-bearing finger and then fell into the Crack of Doom.