Delete pending comments
Spam comments on WordPress sites were the most horrible thing for me in WordPress experience. Then i was looking for a solution for this and finally found this Cool, Useful WP plugin, which is totally FREE. It will save your days & hours with spam problems on your WordPress site.
Resource Link : http://wordpress.org/plugins/delete-pending-comments/
Yoast for SEO
Yoast is a best Search Engine Optimization plugin for WordPress sites. It’s widely used for WP sites and its FREE ! I personally find this is as a SEO specialist. Because, The plugin will teach you more about SEO and shows how to optimize web pages by it self.
Resource Link : http://wordpress.org/plugins/wordpress-seo/
SEO Friendly Images
When you care about the site traffic, Images are playing a major role with search engine traffic. So this is the plugin you can handle it very well. It will be much easy to deal with web site images and alt & title tags for better SEO rankings.
Resource Link : http://wordpress.org/plugins/seo-image/
Its a cool sharing option which you can use for your WordPress site with easy steps. But its more advance on customizing easily for your needs. I personally liked this WordPress plugin and used for my blog too.
Resource Link : http://wordpress.org/plugins/sharebar/
Dig dig is a cool WP plugin which is very clean, professional looking sharing option. you can do customize as your needs.
Resource Link : http://wordpress.org/plugins/digg-digg/