Stat Traq provides detailed statistics in a nice graphical format. It tracks hits, pageviews, sessions, browser details etc.
wordTube will display your own videos, images or sound files on your blog.
WordPress Passwords adds a site-wide password to your posts and pages without the need of .htaccess, users or security levels.
Top Posts by Category displays your best posts, as determined by the number of visits to the post or number of comments.
Distributed Social Networking lets you publish hCards, blogrolls as XFN, allow public/private profiles and adds a messaging system.
Category Converter lets you condense categories on your blog into a shorter list. Seems really useful if over time you want an updated category list while maintaining the posts.
Slightbox is a combination of Slimbox and Lightbox.
Simple Yahoo! Sitemap lets you create a Yahoo! compatible sitemap.