Let's take this baby for a spin, and see what it can do!

[doug*platypus]

It made him undefeatable in battle! Oh, unless you happen to cut it off his finger.

Remember this very simple inequality:

BOOK > MOVIE

The book is greater than the movie. Especially since Sauron reaching out for Isildur and *ahem* exposing his Ring, makes absolutely no sense.

Maybe you're right about the 'good but not great' Ring, I'd never thought about what would have happened if Sauron got It back. Maybe he would have been a little disappointed himself! It might have been just a big anticlimax for him.

The chief danger in him regaining the One was the control it had over the elven rings. It is implied in the book that Galadriel (and probably Elrond as well with his ring of power) is vulnerable, because of all she has accomplished through Nenya. If Sauron regained the One, Lórien would have been exposed. And it would have been better (as is stated somewhere) in this case, if the three had never existed.

It would have been interesting to see a contest of wills between Gandy and Sauron over the control of Narya. It's probable that Gandalf would not be able to use his ring of power anymore in that case. As for undoing all the works of the three, maybe everyone Gandalf had influenced with its help would revert back to how they were before!