I really like Amarok, but from Version 2 onward, the developers 'forgot' that people have MP3-players they use when not sitting in front of their PC (maybe the developers never leave their PC ;-)). So I vote for rhythmbox.

Thanks for mentioning gmusicbrowser, never knew of it, will try it out!

Movie Player as an audio player.
 

Movie Player is not listed. But it is what I like to use to listen to just audio. I enjoy the light show that gets generated. I know, it's just a "gimmick", but I like it.