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.

James Robinson

A simple plugin that enables a shortcode for embedding Gist code in WordPress.
The shortcode has two attributes, the Gist source URL and, optionally, the height of the embedded code window.
<pre><code>[gist src="" height=""]
</code></pre>
The Gist <code>src</code> attribute must be the embed URL, for example: https://gist.github.com/imaginarymedia/316a29936e5e7d709665.js
The Gist <code>height</code> attribute is optional and can be any value with a valid CSS unit measure: em, %, px, vh, etc. It will apply a max-height to the gist.
The plugin also creates UI buttons for both the visual and text editors.
If you have suggestions for improvements, please contact us. via the <a href="https://wordpress.org/support/plugin/wp-gist-embed" rel="ugc">plugin support page</a> and if you find this useful, please <a href="https://wordpress.org/support/view/plugin-reviews/wp-gist-embed" rel="ugc">review the plugin</a>.
Developed by <a href="https://jmr.codes" rel="nofollow ugc">James Robinson</a>.
** TO DO ** 
* Validate the gist src URL

WP Gist Embed

This plugin provides Gist embedding via shortcode as well as adding Gist embed buttons to the visual and text editors.

Pretty Gists vs WP Gist Embed