[Thalion]

It is Glorfindel who at the Council of Elrond declairs that he thinks that Bombadil will not be able to hold off all of Sauron's might if he stands alone...howe this should be interpreted is tough...does this mean that Sauron's might includes all of the Orcs of Mordor as well as the Nine? I would tend to say that it does, and therefore the statement as read properly means that Bombadil can't stop all of Sauron's forces if they are all bent on destroying him as the last stand...but one on one???

...because Tolkien gives no direct inclination either way, I'll give mine...

Bomdabil is not bound to be influenced by the Ring, for which Sauron and all other creatures that we come into contact with in the LoTR are...meaning that Bombadil has some power or majesty that makes him immune to an object, a power that even Gandalf and Galadriel would be corrupted by...although this doesn't initially tell us whether or not he would win in a context mano a mano with Sauron, it does give us some insight...Sauron is bound to the Ring's influence, Bombadil is not...therefore Bombadil has some power in him over the Ring that Sauron does not...this seems to imply that Bombadil would win for no other fact than he can master something Sauron cannot (this isn't exaclty what I mean, but more like Bombadil has more power than Sauron because the ring doesn't affect him...if you take the earlier statement over mastery of the ring literally, it would make a good alternative debate as to whether or not Sauron himself has "mastery" of the ring or he himself is bound to its dominion, meaning that Sauron is moreso corrupted or under the influence of the ring like all others in Middle Earth except Bombadil are...but I digress...)

...here I would also venture to say the following...Sauron was "defeated" by a combination of Elendil and Gil-Galad...neither of which I would consider to have as much might as say the older Eldar or Edan such as Fingolfin, Hurin or Turin(side point)...but I am inclined to say that Bombadil would have mastery over these persons(Isildur, Elendil, Gil-Galad) as even they would fall under the dominion of the Ring(as Isildur did)...since Bombadil can "master" the Ring and they can't...I'd say he trumps them...since they trumped Sauron, I'd say Bombadil wins all...