[Gothmog]

To start with I have to confess something: I haven't read through all the posts in this thread so it is possible that I repeat things that are already said. But anyway, here's my view on this topic:

It's hard to tell who's the master. Of Turin it is said "Master of fate, by fate mastered" and I think this is similiar to the Sauron-Ring case. "Sauron, Master of the Ring, by the Ring mastered".

But why would someone do something as stupid as putting his power in a simple piece of jewelry, making himself vulnerable? Well one thing is for sure, Sauron wasn't stupid. He wouldn't have made the Ring if it wouldn't grant him greater powers. And with it's power to rule over the other rings, it would have given him a strong weapon against the elves and men. Now that plan didn't work as it was supposed to, Celebrimbor suspected something and made the Three. But I think that the Ring still gave Sauron greater powers than he would have gotten without it.

The fact that it made him vulnerable then?. Well, except for not being stupid, we also know of his pride. He wouldn't dream of losing the Ring, he was after all the Dark Lord! Of course it made him vulnerable, but only if it was taken from him and that wasn't supposed to happen.

But can we say that the ring is the true master? I think not. Within lay the power of Sauron, so one can say that it was a part of him. And even if it had it's own powers, it couldn't use it in full without the hand of it's master, as well as it's master Sauron couldn't use his powers fully without the Ring. So it's a give and take relation. The fact that Sauron was destroyed with the ring doesn't prove that it was his master, but they were depending on each other. If there was some other way of erasing Sauron (throw him into the Void maybe?), then perhaps the power of the ring would have been undone with him?