the best mp3 player, if you have a lot of mp3 files WITH TAG information:
 http://third.informatik.uni-kl.de/~rainer/kjukebox/index.html

also a good choice, use this one if you do not have TAG information:
 http://www.rhrk.uni-kl.de/~mvogt/linux/kmpg/index.html

i had tried this some time ago :
 http://www.kmp3.org

for the gnome people:
 grip, cd player and ripper in one application

another one (fine icons ;-):
http://adam.kaist.ac.kr/~wineking/ripperX/

THE FreeAmp:
 a X11 mp3 player

the xmms (something like WinAmp with a lot of features):
 a X11 mp3 player