Some Wordpress plugins are often updated, which is good think. Plugins that are updated are 100% compatible with last Wordpress version and they also are the most secure possible. A plugin that has not been updated for a long time might not work with last Wordpress version and might create a security breach for you website.
With this plugin you can add new functions through admin menu, without editing your themes functions.php
Easy Navigation to next and previous posts using arrow keys or navigation buttons.
WP Backup Complete is a complete backup solution for WordPress. The plugin will backup the Wordpress database as well as the file system.
Easily verify your site with Google Webmaster Tools, Yahoo Site Explorer and Bing Webmaster Center in both Wordpress and WPMU
Retrieves posts and pages with a certain custom field (e.g. to permanently show your most recommended posts in a widget) and displays them in a list.
Simple Youtube Shortcode provides a shortcode to embed youtube videos or playlists, with basic options for sizing the player and styling with CSS.
Allows sorting of posts by title, comment count, and other criteria for various pages, including category pages, tag pages, home page, etc.
Write a post without leaving your site!
This plugin add custom fields for some things on WordPress, term taxonomy and custom object types