Just came across this helpful infographic at WP Template with the most popular WordPress plugins. If you are new to WordPress or long time user, it is always helpful to see what others are doing.
The list with the links comes from the Daily Egg website.
SEO
Spam Checker
Playing Nice with Google
While you’re at it, check out these alternatives to Google Analytics
Other Technical Functionality
- WP Super Cashe
- WPtouch
- Jetpack by WordPress.com
- WP-PageNavi
- Broken Link Checker
- W3 Total Cache
- Redirection
- WP-DB-Backup (Note: According to this website, the plugin hasn’t been updated in over two years, so it may have compatibility problems with newer versions of WordPress.)
Connecting with Visitors
- Contact Form 7
- Really Simple CAPTCHA
- Fast Secure Contact Form
- Share Buttons by Lockerz / AddToAny
- Sociable
- GTrans
- WP to Twitter
- AddThis
- Buddy Press
Content Management
- TinyMCE Advanced
- NextGEN Gallery
- Word Press Importer
- Yet Another Related Posts Plugin
- Smart YouTube PRO
- WP-Polls