Enhance the YouTube videos you embed in your WordPress blog using this plugin. It not only provides the features of YouTube's standard embed, but also extra playback options, relevant user-generated content, and video reactions beyond YouTube.com comments (e.g., Google+ and Reddit). Use it to automatically enhance the viewer experience and engagement around the YouTube videos you embed, for free.
See more here:
http://wordpress.org/extend/plugins/embedplus-for-wordpress/
and here:
http://www.embedplus.com/