Waterloo Plugins

Social Shares uses the Facebook and Twitter APIs to fetch the total number of shares for each of your posts. The number of shares is stored in your database for any plugins to use. Social Shares can optionally display the number of shares on your posts. The number of shares is styleable. You can use the shortcode <code>[social_shares]</code> anywhere in your posts.
In addition, you can sort your posts by the number of shares. You can make a page that displays your posts with the most shares. Simply add <code>?sort_shares=desc</code> or <code>?sort_shares=asc</code> to the end of any WordPress URL to sort by the number of shares.

Social Shares

Get the number of Likes and Twitter Tweets for each post. Sort your posts by share count or display the share count.

d-media

Automatically add InShare buttons to your posts. It works for single pages and loops. 
The plugin features an options page in which the following can be configured:
Display options:
<ul>
<li>Toggle hiding of button in loops </li>
</ul>
Display style:
<ul>
<li>Show button on top or bottom of post</li>
<li>Choose button display style (counter top,counter right,default)</li>
<li>Add breaks before and/or after the button</li>
<li>Button preview</li>
<li>Custom styling option, adds a containing div with classname which you can style in your stylesheet (new since 1.1)</li>
</ul>
<h3>Arbitrary section</h3>

LinkedIn InShare button

Automatically add InShare buttons to your posts. It works for single pages and loops and is display options are customizable.

Social Shares vs LinkedIn InShare button