LordMontie’s — LMB^Box Comment Quicktags plugin is a very comprehensive piece of work. It comes with pre-configured Quicktags and as well customizable i.e. you can add your own Quicktags in the option menus.
Demo: Click on “Add comment” or “Show comment” to go to comments form.
To install LMB^Box Comment Quicktags plugin, follow the Installation Directions in the readme.txt file or in the lmbbox-comment-quicktags.php file. You will need to edit your comments.php theme file in order to display the Quicktags Toolbar. If you are upgrading from an earlier version than 1.5, you will need to make sure that the PHP function call (the code added) in your comments.php theme file is correct with the new plugin (Step 3). You will also need to make sure that your comments.php theme file has the right formating and code (only worry about this if you have modified your comments.php theme file greatly)(Steps 3.1 & 3.2). If you are wishing to use Popup Comments and have the Quicktags Toolbar be on them too, point your browser to this comment for more info on how to!
WordPress Plugin: LMB^Box Comment Quicktags