Customized first post techniques

You shouldn’t need to do any special queries for this. Here is one way to accomplish it

/**
 * conditional check ensures special class only shows on top post on first page.
 * if you want top post on page 2, etc. to have special class, just set $first_post to true
 */
if( (int) get_query_var( 'paged' ) > 1 ){
    $first_post = false;
} else {
    $first_post = true;
}

if ( have_posts()) : while (have_posts()) : the_post();                 

if ( $first_post ) {
    echo '<div class="post top-post-special" id="post-' . get_the_ID() . '">';
    $first_post = false;
} else {
    echo '<div class="post" id="post-' . get_the_ID() . '">';
}