Don Caprio

As the name implies, this social sharing plugin is simple and loads pretty fast. The buttons do not rely on external resources to load, it’s written in PHP, HTML and CSS.
There’s an option to show the buttons on posts and pages. You can also put the buttons anywhere in your template using this template tag:
<pre><code><?php dc_social_share_tag(); ?>
</code></pre>
You can also display using this shortcode in single posts and pages:
<pre><code>[dc-social]
</code></pre>
Please note that these buttons do not show share counts. The essence of the whole thing is to keep it very simplified.
The only button that requires a little snippet of JS to work is the Pinterest button but this does not slow down your site in anyway. A demo of the plugin can be seen here: http://geek.ng/

DC Simple Share Buttons

A set of very simple social sharing buttons that loads pretty fast (no javascript, no images).

WP Dev Shed

Ryan Sutana

The easy and simple way to share you blog posts via Facebook and Twitter. Just activate the plugin and go to Appearance > Customize to set your preferences for display. You can choose to display before and/or after content on pages and posts. You can also choose to display the share buttons anywhere in a page or post using the short code [wpdev_social_share]

Social Share by WP Dev Shed

Adds Facebook and Twitter social share buttons to your blog posts.

DC Simple Share Buttons vs Social Share by WP Dev Shed