1. Subscription Options

Is a simple yet very useful plugin for beginner bloggers. This plugin will allow you to add the classical icons for subscription: twitter, rss feed and email of course effortless.

2. Alexa Ranking Plugin

The earnings from your website are pretty important, the most effective way of getting high profits from your website is of course by selling ad space. In order for advertisers to buy ad space, they need to see what’s your alexa rank and if they like it, they will buy ad space from your blog.

3. Twitter Blender

Is a wordpress plugin that displays twitter updates in a simple widget box in your sidebar. The Twitter blender also has an updates archive.

4.Wordpress Newsletter Widget

Wordpress double option widget bulk email plugin for newsletter subscription will allow users to subscribe to your newsletter and also you will be able to manage the subscriptions.

5. Recent Comments by Entry

As I believe you figured out, the Recent Comments by Entry plugin will display the latest comments and also the entry where they were posted.

6. Post videos and photo galleries

Helps you to easily maintain your media works and place them into your blog sidebar.

7. WP Carousel

WP Carousel is a plugin that create a carousel with a category’s posts, and you can put it anywhere on the sidebar or blog.

8.Ad Code Widget Plugin

This plugin helps you to easily maintain the ads you display in your sidebar and in your blog. It was created by Primo Themes and it supports any image format and also any size and also you can add HTML/JavaScript/IFrame/etc codes.

9. Login With Ajax

This is a pretty cool widget plugin that allows your blog members to login. Using the ajax technologies, “Login with Ajax” will improve the aspect of your login page and also will impress all of your members.

10. Visitors Map and Who’s Online Widget

This will display a cool who’s online widget and also you will be able to see where the user comes from by using this great geographical positioning system.

11. Twitter Bubble

Will display your twitter updates in a simple widget who has the shape and the design of a twitter page included in a cool twitter bubble.

12. Post Google Map

If the blog you own is a business one and you have to show people where they can find you, Google Map is always the best solution. Post Google Map will help you to do that effortless.

13. Simple Flickr Photos

Nowadays everyone has a Flickr account and everyone wants to share their photos with friends and why not will all internet users. Simple Flikr Photos allows you to add a Flickr widget with your latest added photos.

14. PayPal Donations Plugin

This is definitely a must have plugin for developers and people who are offering services for free. Paypal was always the best friend of this kind of people and it helps them everyday.

15. Collapsing Archive

Being able to collapse your archive will save you some useful space in your sidebar. Collapsing archive is the plugin you want for this, and it is based on javascript.

16. General Stats

General stats counts almost everything from users, number of posts, days, and adds a simple widget to display this stats.

17. Tag For Me

If you own multiple blogs or websites, Tag for me will help you to display your stats using their widget.

18. Flash Tag Cloud

Displays the tags into a very interesting and cool way. The tags you write more are of course bigger and the ones that you don’t are smaller. The plugin is using the action script programming and is very stable.

19. Page Spot

This actually lets you to configure multiple types of sidebar and choose which one to display.

20. WP FlashTime

Adds cool and flash clock. This will help you to improve the design and it will make your site more dynamic. The plugin also contains over 25 different clocks.

21. Quick Adsense

It is a flexible and easy to use Adsense management plugin. With quick adsense you will add and maintain your adsense ads in no-time.

22. Sidebar Tabs

Includes a widget which adds multiple functions displayed in other tabs.

23. iContact Widget

Add the iContact ‘Automatic Sign-up Form’ to your sidebar with this widget. Simply paste the code from the form you created in iContact into this widget. Your form will be converted into HTML (instead of Javascript, which takes more time to load).

24. Display Widget

Choose which widgets to display and which widgets to hide. You can also choose to do this on which page of your blog you want.

25. Visual Categories

This plugin enables you to build “category entries” which contain a link to the category and which may contain a link to the category’s feed, an image, the time stamp of when the category was last updated, and the current count of posts in the category.

26. TinyFeed

A simple ajax plugin that loads a micro feed on your sidebar.

27. Flash Mp3 Player

It displays a cool flash player in your blog sidebar. You will be able to choose which MP3 file to listen and is more like the youtube player.

28. Category and Page Icons

This obviously adds icons to your categories and pages links.

29. ThemeSwitch

Using this plugin will allow you to easily change the current theme of your blog.

30. Gallery Widget

Gallery Widget is a simple plugin that let you show the latest/random images of the wordpress media gallery inside a widget, directly in your templates (it is possible to choose some categories to be included/excluded) or in posts/pages using a shortcode (see faq on how to use them).