I display statistics on my forum, but not with a plugin I just did this:
<div id="onlinelist">
<?php include_once("bb-includes/statistics-functions.php"); ?>
<h2>Statistics</h2>
Our users have made a total of <?php echo get_total_posts(); ?> posts in <?php echo get_total_topics(); ?> topics. <br/>
We have <?php echo get_total_users(); ?> Registered Members. Our newest member is <?php if ( $users = get_recent_registrants(1) ) : foreach ( $users as $user ) : ?>
<a href="<?php user_profile_link( $user->ID ); ?>"><?php echo get_user_name( $user->ID ); ?></a>
<?php endforeach; endif; ?>
<br/>
<p><?php show_online_users(); ?></p>
</div>
This could be easily pluginized though, I might do it. But instead of waiting, I recommend doing it yourself or just pasting this on your front-page, wherever you want it to be displayed.
It is quite interesting 
. Perhaps “top topics by posts” and “top topics by views” will overlap.
