MP3Gain - A free automatic mp3 volume normalizer.
VLC Media Player - VLC is a free and open source cross-platform multimedia player and framework.
QMP3Gain - Graphical user interface front end supporting MP3Gain engine which analyzes and losslessly adjusts...
AIMP - AIMP : Free Audio Player : Официальный сайт программы
wxMP3gain - Needs to be compiled.
foobar2000 - An advanced freeware audio player for the Windows platform.