True Hero: Frodo or Samwise?

[Faramir Jones]

I think the reason, Lotrelf, why Tolkien said that without Sam Frodo would have failed is because Sam, when he thought Frodo was dead, decided to continue the quest to Mount Doom without him, and took the Ring. It's clear, from what he said in the chapter, appropriately entitled 'The Choices of Master Samwise', that if Sauron got his hands on the Ring that the War would be lost, and everything he knew and loved would also be lost.

Not only did he take the Ring; he managed to resist its blandishments, using his hobbit common sense. He was successful until after he rescued Frodo and freely gave it back to him. He was one of only two people, including Bilbo, who were able to voluntarily give up the Ring.

Sam makes his decisions, particularly the one to take the Ring, completely on his own. He is in no position to ask anyone for advice; but he goes ahead and makes what turns out to be the right decision, the one that wins the War.