Default posts order by name in admin

functions.php

<?php
/*
 * This snippet overrides the default post ordering in the edit posts table (admin),
 * while keeping other post ordering options (by clicking on the table headings)
 * still available. Useful for CMS-like setups and could be tweaked for
 * custom post types as well
 *
 * Konstantin Kovshenin
 * http://theme.fm
 */
add_action( 'pre_get_posts', 'my_pre_get_posts', 10, 1 );
function my_pre_get_posts( $query ) {
	if ( $query->is_admin && ! isset( $query->query_vars['orderby'] ) ) {
		$query->set('orderby', 'title');
		$query->set('order', 'asc');
	}
}