Websites Created by WordPress, Drupal and Joomla

As a beginner, I'm going to build a good-looking video streaming website, but want the easiest way to build. I'm looking for a user-friendly CMS to create the main structure of my site. Please have a look at: http://www.threehosts.com/ratings/comparison-software/wordpress-vs-joomla-vs-drupal.html. As you can see they have provided a collection of websites created with WP, Drupal and Joomla. How can I understand if these websites are really built with the mentioned software? And how can I know if they have used any template for their sites or they have only used the mentioned CMS? Because some of these websites look really great and professional! I want to know this because I'm on a tight budget and don't want to pay for any template or theme.

I have used EZGenerator for years. Thinking about a new forum site, but it is very easy to choose from a large number of themes, and get your site built. You pay for the software but that includes all the themes. The link you posted looks like one of those pages put up to get users to buy wordpress. I tried Wordpress once and it drove me nuts! Might be better now.