jStackMenu is a jQuery UI widget which transforms the children of any element into a beautiful stack menu. The menu opens with a smooth animation and it is possible to control. In order customize it more, it also has support for events.
xBreadcrumbs (Extended Breadcrumbs) is a jQuery plug-in to create categorized breadcrumbs for your site. This may be useful if your website has a deep structure and you want allow your visitors to quickly navigate through one section of the site to another. xBreadcrumbs works with unordered lists (UL/LI) which would make your breadcrumbs fully optimized for search engines. An SEO freindly breadcrumb has many benefits.
jQSimpleMenu is a multi-level hierarchical jQuery drop down menu that helps you add drop down menu in your website without writing a single line of code.