VLC Media Player - VLC is a free and open source cross-platform multimedia player and framework.
Mixxx - The most powerful free DJ software in the world.
AIMP - AIMP : Free Audio Player : Официальный сайт программы
VirtualDJ - Virtual DJ Software - MP3 and Video mix software for DJs
foobar2000 - An advanced freeware audio player for the Windows platform.
Traktor Pro - Flagship DJ software with four decks and a stunning range of creative features for maximum freedom in DJing.