To Bear a Ring of Power...

[Manwe Sulimo]

Ringbearers:

Frodo: Obviously alone, only hobbit of the Fellowship never to get married; passed into the West the soonest
Galadriel: Was a lot closer to Celebron before she received Nenya
Gil-galad: (Not sure, but) had no children, so probably no wife, killed
Círdan: Unknown marital status, but seemingly lonely post; never could make long-lasting friends, as everyone he met left for the West
Gandalf: Wanderer, distrusted by Men. Obviously had no equals, save the other Istari, who he seemed to avoid
Elrond: Wife left for Valinor; two sons fought for Gondor (meaning they did not stay home to help defend Rivendell), daughter married a Man
Gollum: Isn't it obvious? [img]smilies/smile.gif[/img]
Nazgûl: Again, pretty obvious....
Sauron: Really obvious....
Isildur: Not really a chance to become to lonely, seeing as he was killed....
Thráin: Wandered from Ered Luin to Dol Guldur accompanied by only his son (for some of the journeys)

The sole exception seems to be Sam.