Got myself some .avi files but didn’t have a player under CenOS 4.2. MPlayer would appear to rate well as a media player for linux.
yum install mplayer
yum install lame
# Unfortunately mplayer while registered could not be downloaded, tried the hard way
rpm -ivh mplayer-1.0pre7try2-2.i386.rpm
# lame wasn't needed via the manual process, but just in case
Surprisingly, it’s not a GUI interface, but mplayer