Although having too many plugins can become unmanageable and dramatically slow down your blog, there are some plugins which I feel are always a must and can enhance the performance of your blog.
There are 7 plugins which I always install on every blog no matter what its purpose, so let's take a look at each ones purpose and what I use it for.
WP-SpamFree This is an extremely powerful anti-spam plugin that virtually eliminates comment spam.
Finally, you can enjoy a spam-free WordPress blog! Includes spam-free contact-form feature as well.
WP DB Backup This plugin allows you to easily backup your core WordPress database tables.
You may also backup other tables in the same database.
All In One SEO Pack This plugin will optimize your WordPress blog for the Search Engines (Search Engine Optimization).
Which in turn gets your blog and its posts indexed faster.
Google XML Sitemaps This plugin will generate a sitemaps.
org compatible site map of your WordPress blog which is supported by the following search engines: Ask, Google, MSN and Yahoo.
This will enable the search engines to crawl your site much easier.
WordPress Duplicate Content Cure This is a very simple, yet effective SEO plugin that prevents search engines from indexing WordPress pages that contain duplicate content, like archives and category pages.
Ultimate Google Analytics This plugin adds Google Analytics JavaScript to each page on your weblog without making any changes to your template.
The plugin can also add tracking to outbound links, downloads from your own site and mailto: links.
The plugin is highly configurable.
Contact Form 7 A simple but flexible contact form plugin which allows your readers to be able to contact you in a safe and professional way.
So, there you go, 7 vital plugins for you to install on your blog.