First versions of Absolute Comments implemented several features that are now, out of the box, part of WordPress.
Absolute Comments now simply adds a “Reply” link into comment notification emails, prefills the comment reply with the commenter’s name, and adds a few cute icons.
There’s no option or settings: just activate and forget it’s even a plugin.
Official page: <a href="http://planetozh.com/blog/my-projects/absolute-comments-manager-instant-reply/" title="Absolute Comments" rel="nofollow ugc">Absolute Comments</a>
Tip: To keep track of this plugin’s evolution and features, you are advised to subscribe to the <a href="http://planetozh.com/exit/feed" rel="nofollow ugc">author’s feed</a> or follow him on Twitter: <a href="http://twitter.com/ozh" rel="nofollow ugc">@ozh</a>

Ozh' Absolute Comments

Reply to comments from email notification

Thorsten Ott

Simple widget to extend P2s (and other themes) functionality and display recent @replies for a logged in user in the sidebar. 
It can be also configured to show direct replies to comments or posts without the @username indication.

Mention-Me Widget

11-year old plugin and it still works just fine! Sweet!

It works!

Simple widget to extend P2s (and other themes) functionality and display recent @replies for a logged in user in the sidebar.

Ozh' Absolute Comments vs Mention-Me Widget