Rob Saurini

It’s simple enough to embed a Gist, but the default embedded Gist behavior isn’t as easy to read as it could be. I’ve added line numbers and alternating line colors in order to give the gist maximum readability.
Use
<ul>
<li>You can use the shortcode [pretty_gist id=”gist_id“] to embed the pretty gist directly into a post</li>
<li>You have the option to change the default colors in Settings > Pretty Gists</li>
</ul>

Pretty Gists

Gives you the ability to add Github Gists to your site decorated with line numbes and alternating line color.

Guilherme Baptista

Embed GitHub, Gist or Bitbucket files.
See: https://github.com/gbaptista/wp-git-embed

Pretty Gists vs WP-Git-Embed