Websitecode

This plugin adds a “Delete” link below comments made by logged-in users, allowing them to delete their own comments via AJAX, without page reload. Editing comments is not allowed.

User Comment Delete

Allows logged-in users to delete their own comments via a Delete link under each comment.

Julio Potier

This plugin permits your members to delete their own account. You just can not delete all admin users, of course.
All languages are already supported because i use the internal l10n files form your installation 😉

Delete My Account

This plugin permits your members to delete their own account. All languages supported!

User Comment Delete vs Delete My Account