If you are asking who could have destroyed the Ring, the answer is no one with the possible exception of Tom Bombadil. That has been said on several other threads. Everyone would have succumbed to the Ring's power at Mt. Doom. If you are asking who else could have bourn the Ring and brought it as far as Frodo did, then there are a few people that I can think of that might have. Sam, I think, could have made it to Mt. Doom, and possibly Aragorn. Gandalf wouldn't take it - he said so himself in Bag End. On the whole, I would say Frodo is just the best option.
