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.

Abhik

A lightweight plugin to add Facebook Opengraph in the section of your blog. The Facebook Opengraph lets yor visitors share your content with proper Title, Description and Thumbnail Image.
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The Post Title as OpenGraph Title
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The first image uploaded/found in the post as the Facebook thumbnail. Ability to define default thumbnail if no image is found on the post.
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Custom Excerpt for the Facebook Share/Like description. Brings the first 25 words of the blog post if no custom excerpt is found.
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The Post URL as the Facebook Share/Like URL. Doesn’t matter if you have pretty permalinks on.
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Here is a live demo on my <a href="http://www.itsabhik.com/wordpress-opengraph-plugin/" rel="nofollow ugc">WordPress Opengraph Plugin</a> Homepage. If you find my plugins useful, add me in your circles on <a href="https://plus.google.com/106671843900352433725?rel=author" rel="nofollow ugc">Google +</a>. Don’t forget to check my blog <a href="http://www.itsabhik.com" rel="nofollow ugc">ItsAbhikDotCom</a>.
If you like the plugin, please vote a 5 Star. ===>>
Thanks

Opengraph and Microdata Generator

Adds Facebook OpenGraph Meta Tags to head for a better social sharing experience.

Open Graph Pro vs Opengraph and Microdata Generator