Akismet
Is a spam filter that checks your comments against the Akismet web service to see if they are spam or not, also checks the trackbacks for spam.
Ultimate Tag Warrior is a tagging plugin, that’s heavy on tag visualization.
Best Tag system for WordPress. You can use categories and tag system on one website which is very cool.
Execute PHP code in posts or static pages. When this plugin is on you can add php code to static pages or even posts.
This generator will create a Google compliant sitemap of your WordPress blog.
Speeds up posting by moving generic pings to execute-pings.php.
Creates a mail form with multipart verification, various messages and an auto redirect on successful send. It is much more easy to contact with website author.
Implements a dynamic archive, the best archives system i know.
