I thought of something driving to work this morning. Sauron made the ring to control all the others and bring Middle Earth into darkness.
Isildur knew full well what the ring was, but chose not to destroy it. He hope to harness it's power so that his kingdom will not fall. Isildur was killed at the massacre of the Gladden Fields.
Deagol found the ring and was murdered by Smeagol. Smeagol used the ring for mischief until he was driven out of the village. He went under the Misty Mountains and used the ring to turn invisible and fish in the lake and pick off a few unsuspecting little orcs.
Bilbo found the ring and in the Hobbit used the ring to turn invisible. In the Shire, he used the ring to turn invisible and hide from Sacksville-Bagginses. Frodo inherited the ring and used it a small number of times (once by accident in the Prancing Pony) and twice turn invisible and escape. (Weathertop and Boromir).
Boromir lusted for the ring because his aim was to use the ring much like Isildur did.
Galadriel lusted for the ring because she had rebelled against the Eldars and went into exile. She determined that she would set herself up as Queen of Middle Earth. She was forbidden passage to the Gray Havens until she repented. When she refused the ring and refused to act on her "rebellion", then she rewarded and allowed to come to the Gray Havens.
Sam used the ring to hide from Orcs and follow them after they found Frodo in Shelob's cave.
Frodo, at last claimed the ring on Mt. Doom put it on and disappeared.
Now, there is a brief history of the ring.
Okay... why bring all that up? I wonder if the ring can only corrupt you if you know what you have in your possession.
The one who had the ring the longest was Smeagol. A simple Stoor Hobbit. And even he doesn't wish to become a dark lord. In the Two Towers he holds a conversation with himself and says... I will keep the ring and become Lord Smeagol... Gollum the great. Then he listed what he would do... he would repay Sauron for torturing him, and Sam for being rude to him, but to Smeagol, the main benefit of the ring was to provide him fresh fish from the ocean three times a day. Smeagol doesn't want the ring for power. He wants the ring because it is precious to him and by it he gets food.
The danger of the ring was that it would get to Sauron who would know how to use it. I wonder if any of the above-mentioned (with the exception of Galadriel) would ever be so corrupted that they would have replaced Sauron as the Dark Lord.