I cannot decide, to be honest. I love them both. But now when I think about it, book-Boromir is very dull compared to movie-Boromir, so I'll have to go with my favourite dwarf Thorin. Despite how greedy he is sometimes, he has heart and do truly like Bilbo beneath the surface.
has a much greater personal journey during their [the dwarves] Quest, than Boromir does. Boromir was, however, an important part of the Fellowship. It just takes more time to understand and sympathise with the character, especially by the end of FOTR. There are many similarities between the two as well - they both die from their misdeeds.
The pressures Boromir dealt with were about keeping his father appeased and protecting his people which made him more succeptable to the Ring's lure. In his mind he sees the definite possibilty of the demise of his people, and sees himself as all that stands in the way of sauron and his minions. He fights to the death to protect Merry and Pippin and atones for his sin/fault. He doesn't fully realize til his death that Aragorn's and his purpose are the same.
He's not a bad or evil guy, but I like Balin better. Thorin is doing OK in life and takes the quest out of greed and for personal honor/revenge, he doesn't have to do it.
He's arrogant sometimes and greedy, and responsible for his own end, but I love him. If it weren't for him (and Gandalf, of course!), Bilbo would never have had any adventures. Can't wait for movie!Thorin.
Boromir's always made me nervous in both the book and the films. I'm not sure why. His thinking makes sense within his frame of reference, and he's under pressure from his father; his fall is understandable. Maybe it's because he shows up in Rivendell coincidentally in the book -he wasn't invited; he comes looking for aid. Maybe it's because he keeps his thoughts to himself more than Thorin does. Maybe it's because we never get the chance to see him in action as a real leader of Men.
They're both very similar in terms of being basically good characters with tragic flaws who are redeemed in the end, but Thorin seems more likeable somehow.
If it were movie-Boromir it would be a VERY tight call as this is one area I can unreservedly give credit to Peter, Fran, and Philippa for truly bringing forth something I didn't read but was DEFINITELY there from the book and made it so bittersweet that 11 years later I'm STILL crying when Boromir dies in the film. But taking only the books into account (which is only fair since we have yet to see Thorin on screen except in the Rankin-Bass version) then yes, Thorin Oakenshield gets the nod for the depth of his character and the believability with which Tolkien gets us to accept dwarves as a living,breathing, race of substance and philosophy.