gistfile1.php

<?php
$post_types = get_post_types( array('_builtin'=>false, 'publicly_queryable'=>true, 'show_ui' => true) );

foreach ($post_types as $key => $post_type) {
    $posts = get_posts( array("post_type" => $post_type, "posts_per_page" => 1) );
    foreach ( $posts as $post ) : setup_postdata( $post ); ?>
        <li>
            <a href="<?php the_permalink(); ?>"><?php the_title(); ?></a>
        </li>
    <?php endforeach; 
    wp_reset_postdata();

};?>