WordPress is one of the best platform for blogging because of it’s many handy features. One of them is WordPress plugins. 
There are various wordpress plugins which you can use on your blog to enhance your wordpress blog. Instead of covering all the plugins, I quickly cover two under-rated but must have wordpress plugin.
No self ping WordPress plugin
When we interlink our posts in wordpress, new post send a ping to old post, which shows under trackback comments. Though I personally not like the idea of showing own article in Trackback comments and making no difference between related posts. No self ping wordpress plugin , disable the pinging your own blog posts.
Maxblog press ping optimizer
The power of blog is its pinging system. When we write a post , it ping all the servers listed in your Settings > Writing. 
Though one major flow in WordPress is when you edit your old blog posts, it also ping the servers, this create ping spam. Some time excessive pinging leads to ban your website on those ping service. One other problem is with wordpress schedule. When you create and schedule your blog posts, wordpress again ping the server at the time when you hit the schedule button. This is a major problem for bloggers who use WordPress time stamp (schedule) features.
Ping optimizer plugin, stop pinging ping servers when you edit/update or schedule a blog post. It will ping the server only when a new post is published.
Do share with us any such plugin which you think is under-rated and should be a part of any wordpress blog?