Nader

The “Most Comments” plugin displays as the name says posts with the most comments. You can either use the widget in the sidebar or integrate the plugin as template tag in your theme files.
Features:
<ul>
<li>Limit the amount of posts to be shown</li>
<li>Show comments from a specific post category</li>
<li>Exlude posts without comments</li>
<li>Select a time range (last XX days) of posts to be taken into account</li>
<li>Customize the design template via the settings page</li>
<li>Place a widget in your sidebar</li>
</ul>
More Information & Feature Description: 
http://www.brandinfection.com/wordpress-plugins/most-comments/
<h3>Configuration</h3>
You can configure the most comments plugin to your needs. Options can be found under the menu <code>Settings > Most Comments</code>

Most Comments

Display posts with the most comments, as a widget or on a page using the template tag. Customize the look with specific settings.

mrsajith

If your wordpress blog has a better page rank, here is a better chance to reveal it to your blog readers. That is WordPress Page Rank Plugin Show-My-PageRank. What you want to do is just download this plugin and activate it. All of your wordpress post automatically tagged with your google page rank. This will increase your readers interest. More page ranked articles / post get more readership. Just try. Remember , you DON’T need to enter your page rank manually; This plugin automatically pull up your page rank directly from server each time (Live Results)
You can also add your page rank any where in your blog by <code><?php wp_show_my_pagerank() ?></code>
Features:
<ul>
<li>Live Page Rank : You need not to specify your page rank. Plugin automatically checks google server each time</li>
<li>Cute Page Rank Show : Greenish-white combination </li>
<li>Fast loading : It never affect your normal page loading speed</li>
<li>Auto Embedding : All of your post automattically get embedded with its page rank (You can also disable this)</li>
<li>Replaceable : You can place your page rank anywhere as you wish</li>
<li>Readablity : Your user get more enthusiasm when he/she read your blog post if you have better pager rank for that post</li>
</ul>
If your plugin is not working , please mail to admin@sajithmr.com
For details please visit : http://www.sajithmr.com/wordpress-page-rank-plugin/
<h3>Arbitrary section</h3>
If you have any queires / complaints regarding this plugin, please feel free to mail me at admin@sajithmr.com. Thank you
<h3>A brief Markdown Example</h3>
Ordered list:
<ol>
<li>Simple Installation</li>
<li>Cute Design</li>
<li>Better Placement</li>
</ol>
Unordered list:
<ul>
<li>Increment your traffic</li>
<li>increment your blog readership</li>
</ul>
See my blog for technical updates <a href="http://www.sajithmr.com/" title="Technical Digest" rel="nofollow ugc">http://www.sajithmr.com</a> .
<blockquote>
Use Show-My-PageRank and get traffic into your site. Happy Blogging
</blockquote>

Show-My-PageRank

Plugin which exposing your page rank to your blog/site readers. You can configure your page rank  anywhere in your blog

Most Comments vs Show-My-PageRank