VLC Media Player - VLC is a free and open source cross-platform multimedia player and framework.
Google Play Music Desktop Player - A beautiful cross platform Desktop Player for Google Play Music
AIMP - AIMP : Free Audio Player : Официальный сайт программы
GDeskTunes - Multi Platform Desktop Player for Google Play Music™ that integrates beatifully in your OS.
foobar2000 - An advanced freeware audio player for the Windows platform.
Nuvola Player - Cloud music integration for your Linux desktop.