Why was Vilya supposed to be the greatest elf ring?

[Annunfuiniel]

Man-of-the-Wold, great post! I agree with you especially in the next part:

Also, it is the Ring of the Sky, and in a sense, The Three -- Vilya, Nenya and Narya --represent the same gradation of power as personified by Manwe (Lord of the Airs), Ulmo (Lord of Waters) and Aule (Lord of ..., well, he works a lot with Fire).

But I would add one point of view. This may be far fetched but wasn't fire Melkor's main element? At least he used it quite a lot and so does Sauron. So, is there a better way to fight (evil) Fire than with (good) Fire? Gandalf having Narya would then make even more sense in the big picture, he was after all in closest or most direct contact with the fiery nature of Sauron and his kind (balrog).

So, if you must try and find the greatest or whatsoever among the Three then it might be argued that Vilya was the most powerful (like Manwë among the Valar) but not in terms of attack rating or such but in other areas. Manwë wasn't described as the greatest in strength (that was Tulkas), his powers lay elsewhere. Ulmo(>Nenya) was most powerful in his own element and almost equal to Manwë (and more active). And Melkor, well, he was Manwë's brother in Iluvatar's mind, his equal, in some instances described as the greatest among Valar, but his turning to the evil side marked his fall.

All this turned to sound all but sensible now that it's put in words. Bid your judgement and I shall yield to it.