VLC Media Player - VLC is a free and open source cross-platform multimedia player and framework.
Knowthelist - Knowthelist - the awesome party music player Easy to use for all party guests
foobar2000 - An advanced freeware audio player for the Windows platform.
Song Director - Song Director is a program that plays and keeps track of all your music files.
Winamp - Winamp is a media player that allows users to play multiple-file formats, arrange media in a varied file-management system, and play unique media with AAC encoding.
MixTape - Home of MixTape, an OSX application for creating beat matched mixes with simple export to the web or iTunes.