* Get any page's Top most Page ID.
 * Whether it is the direct parent, a grand parent or even a great grand parent it will always return the top most page ID
 * source: http://www.webcitizenmag.com/2010/05/20/how-to-get-top-parent-page-id-in-wordpress/
// Add this function to your functions.php file or functionality plugin
function so_get_top_most_page_id() {
    global $post;
    $ancestors = $post->ancestors;
    // Check if page is a child page (any level)
    if ( $ancestors ) {
        //  Grab the ID of top-level page from the tree
        return end( $ancestors );
    } else {
        // Page is the top level, so use its own id
        return $post->ID;
// to output the page title in your page templates all you now need is 
echo get_the_title( so_get_top_most_page_id( $post->ID ) );