Advanced Tag Entry - Adds more advanced tag management to the post edit screen. By Jennifer Hodgdon, Poplar ProductivityWare.

Akismet - Akismet checks your comments against the Akismet web service to see if they look like spam or not. You need a WordPress.com API key to use it. You can review the spam it catches under “Comments.” To show off your Akismet stats just put in your template. By Matt Mullenweg.

Breadcrumb Navigation XT - Adds a breadcrumb navigation showing the visitor’s path to their current location. For details on how to use this plugin visit Breadcrumb Nav XT. By John Havlik/Michael Woehrer.

Category Cloud - Displays a category cloud, using bigger font and different colors for important categories. Based on Weighted Categories by Matt Kingston By Francesco Mapelli.

Code Markup - A filter that displays <code> blocks nicely while still allowing formatting. By Bennett McElwee.

Flexible upload - Resize picture at upload and make thumbnail creation configurable (like WP1.5), optionally include a watermark to your uploaded images. By Antoine Choppin.

Google XML Sitemaps - This plugin will generate a sitemaps.org compatible sitemap of your WordPress blog which is supported by Ask.com, Google, MSN Search and YAHOO. Configuration Page By Arne Brachhold.

Gravatar - This plugin allows you to generate a gravatar URL complete with rating, size, default, and border options. See the documentation for syntax and usage. By Tom Werner.

IImage Gallery - Simple but powerful plugin for creating image galleries. By Martin Chlupáč.

Recommended Tags - Creates a list of recommended and existing tags (JavaScript must be enabled). There are currently four different settings you can adjust in the file. By CyberNet.

Search Regex - Adds search & replace functionality across posts, pages, comments, and meta-data, with full regular expression support By John Godley.

WordPress search and replace - Lets you search and replace text in posts using Perl-compatible regular expressions — Usage instructions By Manuel Amador (Rudd-O).

WP-o-Matic - Enables administrators to create posts automatically from RSS/Atom feeds. By Guillermo Rauch.

WPG2 - Embeds Gallery2 within Wordpress to share photos, videos and any other Gallery2 content seamlessly into your Blog & Sidebar Content. Documentation, Support Forums, Change Logs By Ozgreg and WPG2 Team.

WP lightbox 2 - Lightbox JS v2 is a simple, unobtrusive script used to to overlay images on the current page written by Lokesh Dhakar. Add rel=”lightbox” attribute to any link tag to activate the lightbox. This plugin integrate its feature into your WordPress blog. By Safirul Alredha.