Global Content Blocks allows you to create your own shortcodes to insert reusable code snippets or HTML including forms, opt-in boxes, iframes, Adsense code, etc, into pages and posts. You can insert them using the shortcodes or via a button in the TinyMCE visual editor toolbar.
AddToAny: Share/Bookmark/Email Button helps people share, bookmark, and email your posts and pages using any service, such as Facebook, Twitter, Google Buzz, Digg, Delicious, and well over 100 more social bookmarking and sharing sites.
Dynamic Widgets gives you full control on which pages your widgets will appear. It lets you dynamicly place the widgets on WordPress pages by setting conditional rules with just a few mouse clicks by role, dates, language (WPML), for the homepage, single posts, pages, authors, categories, archives, error page, search page and custom post types. (review)
Exploit Scanner searches the files on your website, and the posts and comments tables of your database for anything suspicious. It also examines your list of active plugins for unusual filenames.
Simple Facebook Connect is a series of plugins that let you add any sort of Facebook Connect functionality you like to a WordPress blog. This lets you have an integrated site without a lot of coding, and still lets you customize it exactly the way you’d like.
Theme-Check allows you to run checks on the current theme before uploading to WordPress. This plugin uses the same API and is kept more or less in sync with the WordPress.org uploader tool.