What is the best way mark entries as featured?

OK, after reading Rarst post i went with the taxonomy term option.
It was very simple:

1. Just after the register_taxonomy call, i added one line of code wp_insert_term('Featured','filter'); being filter my taxonomy.
2. Then I modified the query in the template, adding the line 'filter' => 'Featured', inside the args.

Now I only see the featured projects in the portfolio page, which was my main goal. Moreover, i can easily list the featured projects in the backend, as well as Quick-edit this option.

UPDATE:

As a side note, if you then wanted to list the categories without the Featured category:

3. Exclude the term by id:

<?php $featured_term = get_term_by('name', 'Featured', 'filter');
$featured_id = $featured_term->term_id;
$args = array('taxonomy' => 'filter', 'exclude'=>$featured_id);
wp_list_categories($args);
?>