WordPress Plugins that Boost up your Blog

Search Regex
Redirection
Bing 404
WordPress SEO
Hyper Cache
FB Open Graph
404 Email Notifier
SlideShare
Smart YouTube
YARRP
WP Optimize
WP-DBManager
Debug Queries
Auto Post Thumbnail
Regenerate Thumbnails
Google XML Sitemaps
XML Video Sitemap
Date in a Nice Tone

.. more you can find on -- http://www.labnol.org/software/must-have-wordpress-plugins/14034/