Here are some great WordPress plugins which you requested:
Add to Any – Social bookmarking, saving and subscription buttons optimized for WordPress, featuring Google Analytics integration, automatic updating and more.
Akismet – The most well known of the anti-spam plugins always comes packed with the latest version of WordPress, so it is always a given it is ready to go.
cforms II – An easy tool for creating submission forms on your site that can be inserted into posts and pages alike by just inserting a line of code.
Entries On Page X – Adds a link on your posts to the archive page so that people can look through your blog in a more chronological order.
FeedBurner FeedSmith – The essential plugin for anyone who wants to use FeedBurner to monitor their number of RSS subscribers.
Google Analyticator – Google Analyticator takes all the work out of adding Google Analytics to your site. Install the plugin, enter your tracking code in the settings, and this handy plugin will place the code where it needs to be no matter which theme you switch to.
jQuery Lightbox – A lightbox plugin that enlarges the image while darkening the background so you can see the picture better.
Google XML Sitemap – An essential plugin for bloggers to generate XML enabled sitemaps to aid with indexing by search engines like Google, MSN, Ask and more. This plugin has said 2.1 compatible for ages now, but it continues to work with the various updates.
MyAdsense – Allows you to manage your AdSense placement in your theme or posts from a centralized settings page. Tired of remembering if you created your account with Sean or sean? This plugin will let you sign in any way you want once it is installed.
PHP Code Widget – This plugin will allow you to post PHP snippets in your post and execute them.
Smart YouTube – Allows you to easily insert YouTube videos into posts, comments, RSS feeds, and gives you numerous options for customizing their display.
Podcasting – Gives you full podcasting support inside of WordPress with tools such as iTunes distribution, support for multiple formats, a built-in player and more.
If you feel that there are better plugins which we have not added to this list, could you please include them in your comments so we can all benefit from them.