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
MPC-BE - MPC-BE is a free and open source audio and video player for Windows.
ServeStream - ServeStream is an open-source application that is intended for HTTP media player streaming, and the media server browser comes with the alluring support for custom online radio and Shoutcast streams.
Audience Media Player - Audience is a modern video player that brings the lessons learned from the web home to the desktop.
MixTape - Home of MixTape, an OSX application for creating beat matched mixes with simple export to the web or iTunes.