1. Entry Views
This plugin is tracking views on your posts page, and showing it to users.
2. EWWW Image Optimizer
Reduce file sizes for images within WordPress including NextGEN Gallery and GRAND FlAGallery. Uses jpegtran, optipng/pngout, and gifsicle.
This plugin optimizes your images for faster loading and it is good for SEO.
3. Mark New Posts
I like this plugin very much, it puts a red dot before title of the post published since visitors last visit.
4. NextScripts: Social Networks Auto-Poster
Automatically publish your posts to Facebook Page/Profile, Twitter, Google+ account etc.
5. OneSignal Push Notifications
Setup this plugin so your visitors can sign up for desktop notifications when you publish a new post.
Much better than email? Huh
6. reCAPTCHA in WP comments form
Definitely a must-have plugin, shows a reCAPTCHA in your comments form.
Spammer proof 100%
7. Simply Polls
Create pools within your posts and ask visitors about their opinion.
8. WordPress Social Sharing Optimization (WPSSO)
Automatically create complete and accurate meta tags and Schema markup for Social Sharing Optimization (SSO) and SEO.
9. Yeloni Exit Popup
Exit Popups are the best way to engage visitors leaving your website. Show offers, social buttons, email signup forms or customize it as you like.
10. SyntaxHighlighter Evolved
Easily post syntax-highlighted code to your site without having to modify the code at all. Uses Alex Gorbatchev’s SyntaxHighlighter. TIP: Don’t use the Visual editor if you don’t want your code mangled. TinyMCE will “clean up” your HTML.
If you have some plugins that you would like to recommend, please do so in comments bellow.