In reply to Jeff Chandler.

My vote goes for emoticons as a "jetpack module". All of old, new and other open source emoticons should be bundled where a user can select their favourite one. I use "kaskus emoticons plugin" and it works in comments too. Kaskus has big enough library to use different emoticons in posts and comments. It'll not work if you have turned on jetpack commenting system, only theme default comment system is acceptable. :)