Who's the real lord in this movie?

Funny, I watched the whole trilogy, and have seemed to forgot it all. Well, Lord of the Rings, I guess that was answered in the Third One, "The Return of the King", but still King, not Lord. But then, I guess the Gollum even, since he had the ring in the first place, then had it stolen from him by Bilbo Baggins. I guess it just depends on your own opinion.

The 'One Ring', the ring they wanted to destroy, can control the other rings that were given to the other races in Middle-Earth. So, essentially that 'One Ring' is the lord of the rings, together with the one who bears it and can hold its evil.