[mtgx]

What are they using? Besides iTunes.

[cdcarter]

And a surprising number of people now use Spotify or Pandora for their primary music interface.

[For_Iconoclasm]

Most people that I know use foobar2000.

[mariusmg]

Yeap, foobar2000 is basically the "standard" now.

[tatsuke95]

iTunes and WMP, mostly.

To be honest, I don't know what else people are using. It's one of the places I've had to do the least research in software. WinAMP has been a stalwart for over a decade.