Display your top commenters or authors in a widget.
Display the list of authors with gravatar image and show the total number of post count on hover
Top Author list By Count Post
Elite Members is a WordPress plugin for displaying top contributors/authors in a site.
Display a feed of an authors content from TorqueMag
No Nonsense Authors List provides the multi-author blog owner with a shortcode which can be used anywhere on their WordPress blog to display a neat an