This is my favorite version:

Verse 1:

Joy to the world!

Sauron is dead!

Isildur took the Ring.

But then he got shot,

And then the Ring was lost,

Till Deagol found the Ring

And Smeagol took the Ring

And then he became a deformed hobbit.

Verse 2:

Bilbo found the precious,

And gave it to Mr. Frodo,

Who then was chased

By nasty ring wraiths

And run, run, run he goes!

And run, run, run, he goes!

And run, and run, and run he goes!