LogFAQs > #961578749

As long as the One Ring exists, Sauron does with in Middle Earth. So controlling the ring is essentially a belief you can control Suaron himself. The end result sooner or later. The weak end up dominated by him. The strong, the way I see it, end up mantling him in almost a Elder Scrolls sort of way, but you ultimately end up him and a vessel for him.

Consider some of the following situations

Isildur is a great man in power and ability. He thinks he can control the ring. He'll end up broken too sooner or later but he ends up losing the ring.
Semagol is diminutive and already sort of strange. He likes to skulk and hidden places and roots. So when he takes the ring, he lives his desires. Skulks and lives in a mountain. He is also a precursor to Hobbits and therefore has some natural resistance and he doesn't have a great desire domination. He also doesn't have a lot of power to augment. Ring makes him invisible and it prolong his life.
Bilbo is a hobbit and rather eccentric by their standards. Still, he mainly likes the joys of the hearth and simple pleasures. Little desire for domination or power. Ring makes him invisible and prolongs his life. Ring has a diminished effect on him but it takes it toll, as it does with Smeagol, over time and with usage.
Frodo is like Bilbo for the most part. Wears the ring less though and possesses for way less time.
Gandalf is offered the ring. He would bad news with it. He's a Maiar like Sauron. His would be greatly amplified. He would try to good, but would ultimately be twister towards Suaron's goals.
Saruman would be similar to Gandalf but worse. He was more powerful at the start. He wants the ring because he sees no other way to actually stop Sauron. Hopelessness broke him. He would be dominated quickly. He accuses Gandalf of what he, Saruman,would do with the ring.
Galadreal would be beuatiful and terrible. All would look upon on her and despair. She would be a queen in place of a dark lord. Bad news. Like Gandalf, her intitial intentions would be pure but warped by Suaron over time. He natural powers and will would mean it would take longer but it would happen.

Tom Bombadil has no interest in the ring. It has no power over him at all. He cares so little about it he can't be trusted to even watch after it.
Faramir is an interesting thought. He would end up broke but he has more moral fortitude than Boromir. But his broken relationship with his father and a desire to show his worth I think would be the reason he would claim it. He would get broken quickly due to why he wanted the ring.
Aragorn due to his will and position as Numenorean could wind up with him broke pretty quick too. Likely some sort of tyrant. He knows this and how he resists claiming it. He remembers Isildur.

Note the Ring Wraith are all corrupted kings of men via lesser rings. Galadreal, Gandalf, and Elrond already posses lesser rings too.

These are mainly imo takes but I think it is mainly based on my recollections of the lore.