Comment moderation is a drag. Have your users lend a hand by flagging offensive comments and scrubbing your site clean.
Akismet checks your comments against the Akismet Web service to see if they look like spam or not.
Add the parent comment to comments in the WP Admin area, in order to assist with comment moderation
WordPress plugin to fight with more than 270 referrer spammers (like semalt, buttons-for-website and many more).
Integrate Facebook Comments, Google Plus Comments and/or Disqus Comments on your website
Send comment moderation notifications ONLY to the Author, not to the site Administration address any more.
One click comment approval for WordPress from your Gmail account.
Hide unwanted comments without deleting them. Readers can click on the "Show" link to read the buried comment.