Below are the popular and recommended plugins handy for wordpress installations. I took this list from a video in pluralsight.com.
Popular Free
- Akismet
- Jetpack
- WordPress SEO by Yoast
- NextGen Gallery
- Yet Another Related Posts Plugin
- WP Page Navi
- Google Analyticator
- Widget Logic
- Regenerate Thumbnails
Recommended Free
- WP-DB-Backup
- TPC! Memory usage
- Landing Sites
- PressTrends
- Better WordPress Minify
- Quick Cache
- Quick Page/Post Redirect
- Notifications
- Progress Bar
- Press Page
- WordPress Wiki that Doesn’t suck
Freemium Plugins
- Easy Digital Downloads
- s2member
- Organize Series
- WooCommerce
- WP e-Commerce
Premium Plugins
- Event Espresso
- Gravity Forms
- Cart66
- BackupBuddy
- VaultPress
Premium Plugin Shops
- wpmudev
- CodeCanyon
Ofcourse, this is a list of those taught in the video tutorial. But I feel this is good collection.