Prototype by Greenshady is a specialized parent theme with multiple nav menus, several widget areas, and per-post layouts, allowing anyone from designers to users to quickly creates beautiful sites. The theme is free and open source and there is a support forum and premium services.
Prototype uses the Hybrid Core theme framework taking advantage of nearly all of the Hybrid Core framework features.
Per-post/page layouts (one-column, two-column, and three-column layouts).
Art direction (the ability to upload custom, per-post stylesheets).
Three nav menus (before header, after header, and footer).
Several sidebars (you can add widgets all over the place).
Custom background (uses the WordPress feature for this).
Built-in pagination (no need for a plugin to handle page numbers).
Breadcrumbs, thumbnails, and much more!
Theme homepage: http://themehybrid.com/themes/prototype