Akismet
Akismet checks your comments against the Akismet web service to see if they look like spam or not and lets you review the spam it catches under your blog’s “Comments” admin screen.

Google Sitemap Generator
This plugin will generate a special XML sitemap which will help search engines like Google, Bing, Yahoo and Ask.com to better index your blog. With such a sitemap, it’s much easier for the crawlers to see the complete structure of your site and retrieve it more efficiently. The plugin supports all kinds of WordPress generated pages as well as custom URLs. Additionally it notifies all major search engines every time you create a post about the new content.

Echo
Echo is the next generation commenting system. It’s the way to share your content, and watch the live reaction. You can quickly embed Echo on WordPress, Blogger, or any website and turn your static pages into a real-time stream of diggs, tweets, comments and more. It’s not free, but it *is* cheap and worth every dollar.

WordPress Super Cache
This plugin generates static html files from your dynamic WordPress blog. After a html file is generated your webserver will serve that file instead of processing the comparatively heavier and more expensive WordPress PHP scripts.

Easy AdSense
Easy AdSense provides a very easy way to generate revenue from your blog using Google AdSense. With its full set of features, Easy AdSense is perhaps the first plugin to give you a complete solution for everything AdSense-related.

Google Analytics for WordPress
The Google Analytics for WordPress plugin automatically tracks and segments all outbound links from within posts, comment author links, links within comments, blogroll links and downloads. It also allows you to track AdSense clicks, add extra search engines, track image search queries and it will even work together with Urchin.

Add to Any: Share/Bookmark/Email Button
Help readers share, save, bookmark, and email your posts and pages using any service, such as Facebook, Twitter, Digg, Delicious, and over 100 more social bookmarking and sharing sites. The button comes with AddToAny’s customizable Smart Menu, which places the services visitors use at the top of the menu, based on each visitor’s browsing history.

Twitter Tools
Twitter Tools is a plugin that creates a complete integration between your WordPress blog and your Twitter account.

Broken Link Checker
This plugin will monitor your blog looking for broken links and let you know if any are found.

FD Feedburner Plugin
The Feedburner Plugin redirects the main feed and optionally the comments feed to Feedburner.com. It does this seamlessly without the need to modify templates, setup new hidden feeds, modify .htaccess files, or asking users to migrate to a new feed. All existing feeds simply become Feedburner feeds seamlessly and transparently for all users. Just tell the plugin what your Feedburner feed URL is and you’re done.
If you used blogger, you no doubt integrated your feed with Feedburner, seeing as Google bought it and integrated it, as it adds some wonderful
functionality to your feed with the ‘Add to Del-ici-ous… Digg… Email…. Technorati’ etc, but also its AUTOMATIC pinging to different news services, and sites to tell them you have new content. It also splices in flickr, del-ici-ous or furl, it adds Google Adsense to your posts and so much more. So you will more than likely want to keep this and so it lets you redirect your wordpress feed to your own unique wordpress feed, therefore keeping the AUTOMATED updates and subscribers are none the wiser it is coming from a different blogging platform.
Just need to go into feedburner configuration under appearance to set the feeds and redirects (took me a while to find it, prob should have read
installation. ;o)