Changing comment_count to views

Yes, you have to calculate page views. Do not use plugin as it needs a small piece of code.

Below code will increase pageviews and will store in post meta. Use this code in single.php or loop-common.

if( is_single() ) {

/* Increase post view count by 1 */
        $post_view_count = get_post_meta($post_id, 'view_count', true);

        if( $post_view_count=='' ) {                
                update_post_meta($post_id, 'view_count', 1);                
        }
        else{
                $post_view_count = intval($post_view_count);
                ++$post_view_count;
                update_post_meta($post_id, 'view_count', $post_view_count);
        }
}

Reteriving posts based on views

$popular_query = array( 'post_type' => 'post', 'posts_per_page' => 5, 'order' => 'DESC', 'orderby' => 'meta_value_num', 'meta_key' => 'view_count');

UPDATE

paste your code (as it is, no changing of post_id) like this in single.php.

function custom_categories_listing()
  {
    $categories = get_the_category($post->ID);
    if(!empty($categories)){
        foreach ($categories as $cat) {
            $html="";
            $html .= '
cat_ID) . '" class="odd"';
            $html .= 'title="' . $cat->cat_name . '">' . $cat->cat_name . '
';
            echo $html;
        }   
    }
  }

/* Increase post view count by 1 */
$post_id = get_the_ID();
        $post_view_count = get_post_meta($post_id, 'view_count', true);

        if( $post_view_count=='' ) {                
                update_post_meta($post_id, 'view_count', 1);                
        }
        else{
                $post_view_count = intval($post_view_count);
                ++$post_view_count;
                update_post_meta($post_id, 'view_count', $post_view_count);
        } 

?>
  

Below custom_categories_listing function and above breadcrumb.

Now i think you can figure it out.