This is a list of the 10 most used free wordpress plugins every wordpress should have.
2. Google XML Sitemaps – This plugin will generate a special XML sitemap which will help search engines to better index your blog.
3. W3 Total Cache – Improve site performance and user experience via caching: browser, page, object, database, minify and content delivery network support.
4. Login Lockdown – Limits the number of login attempts from a given IP range within a certain time period.
5. JetPack – Supercharge your WordPress site with powerful features previously only available to WordPress.com users.
6. Subscribe To Comments – Subscribe to Comments allows commenters on an entry to subscribe to e-mail notifications for subsequent comments.
7. Enhanced Recent Post - A plugin for wordpress which enhances the built-in "Recent Posts" widget.
8. Contact Form 7 - It allows you to flexibly design the form and mail. You can manage multiple contact forms as well.9. WordPress Database Backup –