Audacity - Audacity is a free and open-source audio production software suite that includes a surprising array of editing tools and recording systems.
VLC Media Player - VLC is a free and open source cross-platform multimedia player and framework.
Adobe Audition - Mix, edit, and create audio content in Adobe Audition CC with a comprehensive toolset that includes multitrack, waveform, and spectral display.
foobar2000 - An advanced freeware audio player for the Windows platform.
GarageBand - GarageBand is a fully equipped music creation studio for Mac
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.