My gaming box uses winamp. (Running win XP)
My lappie uses xmms (running slax)
My MythTv box uses MythMusic (KnoppMyth)
I've been using Winamp for over 10 years, it's my favorite audio player, though as of recent it's become pretty bloated.
I like the v5 skins, but I don't care for the video player and all the other junk that comes with it.