stesvis

Related articles by tag is a plugin that will display, after the post content, a list of links to posts that have the same tag. It is a great way to have the search engine index all your pages. 
You can tag pages as well so they can be part of the related articles. The plugin comes with a handy widget if you don’t want to use the shortcode. 
Use the shortcode [related-articles-by-tag] where you want the related articles to appear.
<h3>Known Issues</h3>
<ul>
<li>None at the moment.</li>
</ul>

Ivan M

WordPress related posts will show related posts below article in very nice format. Plugin supports different templates for related posts. 
It will help you to increase time per visit by showing to user related similar articles. Plugin is fully configurable and very easy to use.
Plugin features:
<ul>
<li>Simple form for quick and easy configuration.</li>
<li>Shortcode generator (you can use shortcodes to show related posts anywhere you want)</li>
<li>Different templates (boxes and list)</li>
<li>Plugin will use featured image, or first image from article</li>
<li>Quick and optimized code for fast page load</li>
</ul>
Demos:
<ul>
<li><a href="http://demo.wp-resources.com/related-post-testing-article/" rel="nofollow ugc">Example of page with related posts</a></li>
</ul>

Lab404 Related Posts

Show related posts in nice format with image. Plugin is fully configurable and easy to use.

Related Articles by Tag Lite vs Lab404 Related Posts