Wordless Extender is a starting point for everyone: list of commonly used plugins, wp-config.php / .htaccess configuration and security improvements.
Triagis® Security Evaluation is a simple lite-weight plugin to analyze your current WordPress installation, server for security vulnerabilities.
Returns a blank white page if people try to load the wp-config file (or backups of it) in a web browser.
Shows you the values of constants defined in your wp-config.php file
Renews the security keys and salts in wp-config.php on a weekly schedule.
This plugin will automatically set and/or update the Authenication Unique Keys in the wp-config.php file.
Share user roles when sharing the user table between multiple installations.