Bilbo found it. In Gollum's cave.

6 seconds sound clip from the The Lord of the Rings: The Fellowship of the Ring movie soundboard.

You can hear this line at 00:38:18 in the Blu-ray version of the movie.

Quote context

[...]

- Wait. There are markings.

- It's some form of Elvish. I can't read it.

- There are few who can.

- The language is that of Mordor, which I will not utter here.

- Mordor!

- In the common tongue, it says: One Ring to rule them all. One Ring to find them. One Ring to bring them all and in the darkness bind them.

- This is the One Ring forged by the Dark Lord Sauron in the fires of Mount Doom. Taken by Isildur from the hand of Sauron himself.

- Bilbo found it. In Gollum's cave.

- Yes. For 60 years, the Ring lay quiet in Bilbo's keeping, prolonging his life, delaying old age. But no longer, Frodo.

- Evil is stirring in Mordor.

- The Ring has awoken. It's heard its master's call.

- But he was destroyed. Sauron was destroyed.

[...]