The One Object To Rule Them All!

[Cirdan]

As much as I'd like a Silmaril, they just attract waaay too much trouble. Any of the Elven rings of power would be great, or the Elessar:

"And it came into his heart to make a jewel within which the clear light of the sun should be imprisoned, but the jewel should be green as leaves. And he made this thing, and even the Noldor marvelled at it. For it is said that those who looked through this stone saw things that were withered or burned healed again or as they were in the grace of their youth, and that the hands of one who held it brought to all that they touched healing from hurt."