All of the other plugins that I have found only replace the smart quotes after the content has been saved to the database.
This plugin will actually replace the smart quotes before it gets saved to the database.
What does that mean? It means that you will now be able to perform better searches for content without having to worry about those annoying smart quotes.
Not only does this plugin fix smart quotes, it also replaces the ™ (c) and (r) symbols into proper HTML entities.
If you find this plugin useful, please give it a rating.