NS FontAwesome
NS FontAwesome allows you to use CSS classes to display icons. No images to load just pure CSS icons.
The free version of NS FontAwesome requires that you insert the HTML tags such as:
<i class="fa fa-bar-chart-o fa-4"></i>
The PRO Version adds a button to the WYSIWYG editor that opens a select box where you can search all of the available icons and set size and colors.
Here are some examples of font icons in use:
Some social media icon examples:
And of course a Joomla icon: