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.

Alex Sawallich

This plugins enables the famous Google +1-button in your wordpress-installation. The button is shown beneath 
your posts/pages. With this button you can share the permalink to your post/page in your Google+ profile.
You’ve got the possibility to change the look of the button in the same manner, that you can do by using the 
configurator that Google provides: see <a href="http://www.google.com/webmasters/+1/button/" rel="nofollow ugc">Google plus one</a>.

Google+ One Button

Provides a +1 button from Google+ beneath each post/page.

Social Shares vs Google+ One Button