1-All in One SEO Pack
All in one SEO pack is probably the most complete SEO pack for your WordPress blog. You can add title, description and meta keywords of each post and post with the help this plugin.
Jetpack is a collection of different useful plugins such as wordPress.com stats, Twitter Widget, ShareDaddy,a URL shortener, Gravatar hovercards, After the Deadline, shortcode embeds and more to come.
Wp PagNavi adds beautiful pagination to your WordPress blog. You use this plugin with pageNavi style plugin to add beautiful styles to your pagination buttons.
Akismet is the only plugin that comes with the WordPress installtion along with Hello Dolly. Akismet is the most popular comment spam prevention tool available online.
5-W3 Total Cache
6-Google XML Site Map
Google XML site map automatically generate site map of your website so that search engine can better index your website contents.
This plugin redirect all of your feed users feed burner to subscription page and count the number of active rss readers of your site.