<h2>Most commented posts from 2008</h2>
<ul>
<?php
$result = $wpdb->get_results("SELECT comment_count,ID,post_title, post_date FROM $wpdb->posts WHERE post_date BETWEEN '2008-01-01' AND '2008-12-31' ORDER BY comment_count DESC LIMIT 0 , 10");

foreach ($result as $topten) {
    $postid = $topten->ID;
    $title = $topten->post_title;
    $commentcount = $topten->comment_count;
    if ($commentcount != 0) {
    ?>
         <li><a href="<?php echo get_permalink($postid); ?>"><?php echo $title ?></a></li>
    <?php }
}
?>
</ul>

http://www.wprecipes.com/how-to-display-the-most-commented-posts-of-2008

To display a list of your 10 most commented posts from 2008, simply paste the following code on your blog sidebar, or anywhere on your theme.

Display the most commented posts

wordpress

PHP