I've been using GNOME mplayer frontend to mplayer, although not 100% happily.

I just use mplayer (with vaapi) from the command line. It works amazingly that way. I do have gnome-mplayer installed, which is just another front end, but it is really just in case someone else wants to use my computer to watch something.

Have you tried others like maybe smplayer? It is at, but I know many who love it.

I have a massive MP3 collection, and am a DJ.

I have no idea where I'd be without Amarok and it's tool amarok_afttagger. It does seem a little bloated and slower these days, especially when compared to Amarok 1.4 (as a side note Clementine doesn't quite touch Amarok 1.4 yet), but nothing handles my collection management better than it, and it does everything.

To quickly play a single track, Audacious, smplayer, VLC, CLI mplayer, mpg123 all work quite nicely, and I do use them all in different situations.

Audacious

I don't find mplayer here and can't vote.

From using mplayer to play video files I got familiar with its options. I use mplayer for audio as well so there is no need to learn new programs and new options.

Goggles Music Manager for me.

xbmc
 

xbmc: the best of the best.

On my desktop, on my Xios box, even in my android tv stick.

I voted for good ole XMMS looks like that ole Windows product that "whips the llama's ass"! In the Slackware tree, but not in any Ubuntu repository with current desktop support.

rhythmbox.
I use KDE but amarok did lose frequently the db over the years...
rhythmbox is extremely fast and light !

RhythmBox most of the time

Open Cubic Player--probably older and better than everything else on the list, except it does not play 'net radio yet... but that is not what it was designed for, in the early 1990s.

music app
 

audacious for just listening. Audacity for recording.

I actually use mplayer for 98% of everything, audio & video, listening & recording, converting. Great command line flexibility and control.

hog
 

I was impressed by audacious when I first tried it. Quite amazing capability. But I soon quit using it as I discovered it to be a real CPU hog. I run 24/7 background processing on all my boxes and audacious really slows it down compared to alternatives such as mplayer.

mpfc