There’s no reason to use multiple loops to get this effect: The look you want comes from the jQuery Masonry script, which is included in recent versions of WordPress.
Your post list as you describe it is just the standard post index, so use a single standard loop — that is, a WordPress loop, as described in the Codex: http://codex.wordpress.org/The_Loop. Don’t use repeated instances of query_posts(), which will require far more queries and be less performant and more error-prone. Having a single loop will also make your pagination and (eventual) infinite scroll issues disappear.
To use Masonry in your theme, you’ll need to enqueue the script correctly: http://codex.wordpress.org/Function_Reference/wp_enqueue_script
Masonry has a number of display options, and documentation for the script is at http://masonry.desandro.com/index.html
There’s a good introductory-level writeup on building a theme using Masonry on the front page here: http://www.bluelimemedia.com/2012/04/30/jquery-masonry-and-wordpress/ and there are many themes out there that use it if you want to dig into their code for further examples. Note that while the tutorial does a great job of describing how to fit the pieces together, it was written before Masonry was included in the core WP package; you no longer have to download a copy of the script as she describes.