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.

Christian Leuenberg

WordPress comes with a built-in replacement function that turns 🙂 etc. into emojis. If you need to switch this off, simply install and activate this plugin. It’s that simple.

Really Disable Emojis

Disables the automatic emojis (smilies) replacement function. Really! :-)

Simple Smilies vs Really Disable Emojis