Todd Nestor

UPDATE 
Now you can set an option in the new settings page (titled “Herc Sentiment” in the admin bar) to auto-approve positive comments, or un-approve negative comments.
Hercules Sentiment Analysis uses PHP Insight (https://github.com/JWHennessey/phpInsight) to determine whether comments, posts, and post titles are positive, negative, or neutral. This will help bloggers respond to readers who have concerns faster (or delete negative comments if necessary), as well as know what sentiment they are portraying with their post titles and content.

Hercules Sentiment Analysis

Hercules Sentiment Analysis adds columns to the comments and posts tables that show the sentiment of the comment, post title, and post content.

shailesh

“Comment Analyzer” adds a custom field(Sentiment Type) at edit comments section. After this plugin activation, whenever user comment on your post. 
It will get moderate on the basis of open source third party library.

Comment Analyzer

"Comment Analyzer" is a plugin that helps you moderate the comments on your WordPress site. It will analyze user sentiment i.

Hercules Sentiment Analysis vs Comment Analyzer