Songbird is a open source music player, a digital jukebox and and a web browser, all in one. Like Winamp, it supports extensions and skins feathers. It supports a variety of formats and is an excellent option for organizing your music files in your system.
It is built from mozilla and it has a web browser inbuilt within for searching for extensions and plugins. This can be even used for normal browsing purposes Songbird is an advanced music player which even permits use of addons to do amazing things like displaying lyrics of songs while playing etc.
Songbird is available for Windows, Linux and Mac platforms. Personally recommend you to give songbird a try, you will really get to like it.
Here included a video tutorial on how to install this fantastic player on your Ubuntu system.