3hmedia

WP LikeJS includes a nice jQuery driven Like Box Popup Box onto your Website or Blog, which pops up when the user is scrolling your page down. You can choose how much px have to be scrolled before the LikeJS Box is displayed. 
Also you can change the headline of the Box for your communication with your visitors like “Follow us on Facebook” or whatever you want. 
The script is very smart and loads fast and is compatible with all mayor browsers.
Demo: http://www.like-js.de

WP LikeJS

WP LikeJS includes an eyecatching Facebook Like Box on your website. You'll get more Fans with LikeJS than with an usual Like Button and it locks …

CRUDLab

CRUDLab Facebook Like Box allows you to add Facebook like box to your wordpress blog. It allows webmasters to promote their Pages and embed a simple feed of content from a Page into their WordPress sites.
<h4>Features</h4>
<ul>
<li>Developed according to Facebook Graph API 2.3</li>
<li>Display/Hide Fanpage cover photo</li>
<li>Ability to Share Fanpage</li>
<li>Two color schemes (Light and dark)</li>
<li>Display like box using shortcode</li>
<li>Display like box using php function</li>
<li>Display like box to homepage only</li>
<li>Display like box on homepage or all pages.</li>
<li>Display like box on specific pages.</li>
<li>Display like box first time or forever. </li>
<li>Compatible with all type of themes. </li>
<li>Allow user to display fan box to logged or non logged in or both</li>
<li>Show or hide faces</li>
<li>Show or hide posts</li>
<li>Show or hide header</li>
<li>Show or hide border</li>
<li>Set height and width</li>
<li>ON/OFF Indication</li>
</ul>
<blockquote>
 Docs & Support 
You can find <a href="http://bit.ly/1MFw2H5" rel="nofollow ugc">docs</a>, <a href="https://wordpress.org/plugins/crudlab-facebook-like-box/faq/" rel="ugc">FAQ</a> and more detailed information about WP Like Button on <a href="http://crudlab.com/" rel="nofollow ugc">CRUDLab.com</a>. If you were unable to find the answer to your question on the FAQ or in any of the documentation, you should check the <a href="https://wordpress.org/support/plugin/crudlab-facebook-like-box" rel="ugc">support forum</a> on WordPress.org. If you can’t locate any topics that pertain to your particular issue, post a new topic for it
 Recommended Plugins 
The following are other recommended plugins by the author of WP Like Button.
<ul>
<li><a href="https://wordpress.org/plugins/wp-like-button/" rel="ugc">WP Like Button</a> – WP Like button allows you to add Facebook like button on your wordpress blog. </li>
<li><a href="https://wordpress.org/plugins/wp-tweet-plus/" rel="ugc">WP Tweet Plus</a> – WP Tweet Plus allows you to add tweet button on your wordpress blog. You can add tweet Button homepage, specific pages and posts.</li>
<li><a href="https://wordpress.org/plugins/jazz-popups/" rel="ugc">Jazz Popups</a> – Jazz Popups allow you to add special announcements, messages, tips, offers on your homepage or every page of your wordpress website. You can add text, image or video.</li>
</ul>
</blockquote>

CRUDLab Like Box

CRUDLab Like Box allows you to add Facebook like box to your wordpress blog.

WP LikeJS vs CRUDLab Like Box