Very interesting arguments, Captain.
I've been considering this problem,
TGWBS...
Without Bilbo, Sam wouldn't have been what he was because he wouldn't have been told stories about the elves and things, wouldn't have learned his letters, and wouldn't have met with the upper class at all (Frodo, Merry, Pippin...).
Without Sam, Frodo would have perished before he made it to Mordor.
Without Frodo (or with Frodo perishing before making it to Mordor), the entire quest would have failed and everyone would have died or lived under slavery anyway and everything would have been in vain.
How's that for reasoning? It accepts the three most important and argued over hobbits and...I doubt it will be the case, but it could end the fight.
(I still think Sam's the best!)