The years and dates I’ve given are only to illustrate the relative ‘lifespans’ of each, and ‘circas’ are used very liberally, so there may very well be other slip-ups. (And just for clarification, immortals and others who live well into the 4th Age, I've set the outer limit of their age at the year 172 - the year of Findegil's translation).Note, the scores start to rise considerably from here on in: in fact, #1 will virtually triple #21.
#20 [349pts] Elrond Half-elven (1A 532-?: 6700yrs)
As Círdan opened the top-40, this Master bit-player fittingly opens the top-20, as well he should being the 1st to appear of the principle Ring-bearers during the War of the Ring. My guess is that if the question went out to all Tolkien fans who they think should rank 20th overall in importance, Elrond would come to more minds than any other.
#19 [378pts] Bilbo Baggins (3A 2890-?: ?yrs)
Whether his bringing the One Ring back to the Shire from the hands of Gollum was his major contribution, or his leaving it willingly for Frodo, or maybe his instigation of the written words we have in front of us, is debatable. Regardless, the character that many of us were introduced to 1st comes in a well-deserved #19.
#18 [386pts] Finrod Felagund (YT 1300-1A 465?: 2381yrs)
Apart from his leadership and Kingship among the Noldor from Valinor to Nargothrond - significant enough, being the senior of the House of Finarfin in Middle-earth - he was 1st to encounter Man, whom he instructed; he bestowed the Ring of his father from Valinor upon Barahir, an heirloom lasting beyond Aragorn; he joined Beren on his Quest for the Silmaril, saving him heroically; and was talented, powerful, and wise beyond measure.
#17 [399pts] Saruman the White (?-3A 3019: 54,900yrs?)
Another example of what could have been. Though the Brown Wizard only managed to rank 144th; and the Blue Wizards barely crack the top-800; the Grey-come-White Wizard will show just where Saruman should have been. However, Curunir's overall impact and legacy could probably inspire a lively debate.
#16 [413pts] Beren Erchamion (1A 432-504: 72yrs)
With Lúthien’s help, this vegetarian successfully completes his Quest to wrest a Silmaril from Morgoth, and bring it to Thingol to win the hand of his daughter: merely the tip of the iceberg of what makes this hero, whom the Valar deemed worthy of 2 deaths, so special. Plus he's inscribed on Tolkien's grave!
#15 [421pts] Eärendil the Mariner (1A 503-?: 6720yrs)
The 1st character ever, the ultimate hero of the Saga of the Jewels, and one that we can still see in the night sky, Eärendil should probably have cracked the top-10 right beside Frodo, but the Unwins failed to appreciate his story!
#14 [439pts] Galadriel (YT 1362-?: 8546yrs)
She lives during the Years of the Trees in Valinor, knowing Fëanor, Aulë, and Morgoth well; and the 1st Age of the Sun in Doriath, knowing Thingol, Melian, and Lúthien well; and the 2nd Age, knowing Celebrimbor, Gil-galad, and Sauron/Annatar well; and the 3rd Age, knowing Elrond, Elessar, and Gandalf well. In fact one might have to go down the list to Ar-Pharazôn at #50 to isolate a person that she probably did not know or meet or have contemporary events force some form of interaction. The departing ship of the Ring-bearers was more her ship than anyone’s, as last survivor of the Noldor revolt, fulfilling events long before there were Rings. She leaves the lands where her granddaughter was Queen; returning to the lands where her father was still King of the 2nd Kindred, her grandfather still King of the 3rd Kindred, and her grandmother still sister of the King of all Elves!
#13 [453pts] Witch-king of Angmar (?yrs)
Another fitting entry, at the # representing phobias and ill-luck, this former Man places this high for a few functional reasons, not the least of which is the number of monikers that he is listed under. To fully justify this placing however, keep in mind that Evil does play a premium in Tolkien’s world; and to further it if you will, apply the Harry Turtledove theory that the Lord of the Nazgûl was appropriately set to be the next Dark Lord in the 4th Age, the Age of Men. (Tolkien’s textual backflips regarding his death say that he is merely reduced to impotency, and will not be seen again in that Age of the world; further, his New Shadow 4th Age tale re-introduces an ancient evil, albeit cryptically named Herumor. Which links my own pet theory that the Black Captain was also the Black Númenorean – as 3 Nazgûl were – named Herumor conquerer of Harad, as well as the Númenórean Captain of the Black Ship in Tal-Elmar. But of course all this of course has no bearing
). Suffice it to say that a Nazgûl needed to appear, just as a Balrog does, in the top-100 - LotR again promoting one over the other. #12 [457pts] Tom Bombadil (c.55,100?yrs)
Like Mandos, he should probably be either #1000, or top-3. But the literature devoted to the most popular Tolkien FAQ of all brings him in here - his importance certainly being a matter of debate.
#11 [497pts] Lúthien Tinúviel (YT 1200-1A 504: 3378yrs)
Like husband Beren, I can only scrape the surface here: in this case, pointing out that the blood of Lúthien is hinted at as the source of the long-lifespans and healing-powers of her line, which extends through Númenor and Gondor, beyond King Elessar. Of course, Melian is ultimately the source, but then there’s the whole actual-confronting-and-enchanting-Morgoth thing with Lúthien: the highest ranking woman, with beauty unparalleled indeed.
Next, #10 will chime in with 561pts, a full 104pts ahead of #12 – truly the cream of the crop - not even remote anomalies from here on in (if Merry, Pippin, and the Witch-king even were). Well, then again, maybe one needs a little justification to the majority of Tolkien fans!
Sorry, I had to actually do some work yesterday for a change - I will get the final 2 posts in by this evening, I promise. 
The top-500 are done, but I've still got to factor in Wikipedia and Letters to the 2nd 500. And no, there'll be no commentary the rest of the way, just lists.
