Diana K. Cury

Very simple pluing, no configs, no screens, just action! 
Simple Smilies add all WordPress smillies in comments form and a simple javascript let users click them to insert. 
This is a very light plugin, the javascript only loads when in singular/single contexts, also there is no stylesheets.

Simple Smilies

Let users insert WordPress smilies when commenting in you site.

Geek Goddess

As of the release of 4.3, WordPress removed the “Formatting” section from the Writing settings. Included in there was the option to turn off WordPress’s default action to convert text emoticons to image smilies. This plugin does the same thing as unchecking the “convert to smilies” box that used to be available via the settings.

Keep Emoticons as Text

Disables the default WordPress option of converting emoticons to image smilies

Simple Smilies vs Keep Emoticons as Text