QMP3Gain - Graphical user interface front end supporting MP3Gain engine which analyzes and losslessly adjusts...
VLC Media Player - VLC is a free and open source cross-platform multimedia player and framework.
MP3 Normalizer - Improve the quality of MP3 collections by adjusting volume and applying audio effects.
foobar2000 - An advanced freeware audio player for the Windows platform.
MP3Gain - A free automatic mp3 volume normalizer.
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.