Sound

Mp3-Nator 3.0
http://www.twocows.com/mmedia/preview/209207.html
This MP3 player supports skins and comes with drag and drop support so you can easily add music to your play list.

Sonique 1.95
http://sonique.lycos.com/
Sonique is the Web's hottest media and MP3 player. It features support for all the latest audio formats, a killer user interface, customizable skins and visuals, and built-in access to music resources on the Web.

Winamp
http://www.zdnet.com/downloads/stories/info/0,10615,26164,.html
Plays MP3, MP2, CD, MOD, and WAV audio files.