Get ALL post types in WordPress in query_posts
You can use 'post_type' => 'any' for fetching from all post types. See this documentation. http://codex.wordpress.org/Class_Reference/WP_Query#Type_Parameters
Note: It is highly recommended to use WP_Query rather than query_posts. https://wordpress.stackexchange.com/a/1755/27998
'post_type' => 'any',This gets all posts except revisions. https://developer.wordpress.org/reference/classes/wp_query/#post-type-parameters
So your query would be:
query_posts(array( 'post_type' => 'any', 'meta_key' => 'post_views_count', 'orderby' => 'meta_value_num', 'order' => 'DESC', 'post_type' => array('posttype1', 'postype2', 'posttype3') ));
If you want to use get_posts(), the only work around is to use 'post_type' => get_post_types()
Example that returns ALL posts of ANY post type:
$posts = get_posts([ 'post_type' => get_post_types(), 'post_status' => 'publish', 'numberposts' => -1,]);