Sami Keijonen

This mini plugin integrates automatically with Path Theme. Just activate this plugin and you can share your posts on Twitter, Google+ and Facebook. 
Plugin adds these buttons after singular post.
If you want to use this plugin with another theme add this in your template file.
<pre><code>if ( function_exists( 'social_path_media' ) )
 social_path_media();
</code></pre>

Social Path

Share your posts on Twitter, Google+ and Facebook.

Martin Lormes

Automagically adds Open Graph tags to your blog. Control how your posts and pages are presented on Facebook and other social media sites. No configuration needed.
When someone likes or shares your blog on Facebook, your header image is shown. If someone likes or shares a post, the featured image (post thumbnail) is shown. If you haven’t selected a featured image, then the plugin looks for the first image inside the post. If there aren’t any images in your post, then your blog’s header image is shown.
For more information on the Open Graph protocol go to http://ogp.me/

Open Graph Pro

Adds Open Graph tags to your blog. Control how your posts and pages are presented on Facebook and other social media sites. No configuration needed.

Social Path vs Open Graph Pro