Dropdown Menu widget adds a beautiful, CSS only dropdown menu, listing pages, categories of your blog. You can also turn your wordpress navigation menu into a beatiful dropdown menu using this plugin. It allows you to chose vertical or horizontal layout. It supports multiple instances. You can select a theme for your widget from the Dropdown Menu Settings page or you can CREATE YOUR OWN THEME WITHIN SAME PLUGIN!! You can also customize your dropdown menu using CSS. If you want a custom dropdown theme you can request one. Please visit plugin site for more information.