Well, there are thousand of different plugins out there and new plugins come out everyday. Each of them have their own functions and purposes. However, not all the plugins are useful.These are some best WordPress Plugins:
If you are a newbie for SEO (Search Engine Optimization), this is a good one for you to monetize your blog. It is easy to use and manage.
This is a great one to display excerpts of the most recent comments and/or trackbacks in your blog. There is another useful plugin for the same purpose.
A flexible polls plugin. The layout is completely customizable via Admin panels. It also allows you to archive the polls. A good way to do some survey on your blog and to know your reader well.
This plugin is useful if you get a lot of comments on your blog. It breaks your comments into a number of pages. Imagine if your blog gets over a thousand of comments? You definitely need this plugin.
Allows readers to receive notifications of new comments that are posted to an entry. It is useful to get the back the readers for the second visits to your blog. It also help readers to stay updated of those post they’ve commented. It is a must for any blogger.
To show the hottest entry in your blog. The highly discussed contents of your blog can be displayed in a list.
It basically makes your secondary menu activate on mouseover. It save your time on writing or editing in wordpress admin page. A must installed plugin for all wordpress blog.
If you need to generate a XML compliant sitemap for search engines, Google Sitemap Generator is the best choice (supported by most popular search engines: Google, Yahoo, Ask.com, and MSN).