Order posts by meta value - wordpress

I have a meta key and value that keeps a track of people that like the post. However if a post has no likes it has no meta key or value. My WP query is thus:

$args = array(
  'post_type' => 'post',
  'meta_key' => '_post_like_count',
  'orderby' => 'meta_value_num',
  'order' => 'DESC',
  'posts_per_page' => 3
);
$pop_posts = new WP_Query( $args );

The query above just doesn't bring back the right results.

I've tried permutations of the $args below but with still no joy:

$args = array(
    'post_type' => 'post',
     'meta_query' => array(
           'relation' => 'OR',
            array(
                    'key' => '_post_like_count',
                    'compare' => 'EXISTS',
                ),
            ),
    'meta_key' => '_post_like_count',
    'orderby' => 'meta_value_num',
    'order' => 'DESC',
    posts_per_page' => '3',              
);

Both the $args above bring back results - just not the results of the posts with the most likes.

Can anyone help?

Solution

I've spent long time with the meta queries and it usually complicates things.

My advice would be using direct connection to the database through $wpdb, for being much easier. Take this as a start:

global $wpdb;
$posts_with_most_likes = $wpdb->get_results(
                "
                SELECT _post_like_count
                FROM $wpdb->postmeta
                ORDER BY meta_value_num
                "
            );