I use either WMP or the Zune software on my computer, and my Zune on the go. I know I probably should have said something like Winamp or foobar, but frankly, WMP has what I need, and the Zune software isn't too shabby, much better than it's first iterations that I messed with. The idle timer kick-in is really neat, especially if it recognizes the band or singer you have playing. I have about 15GB of music now, and the rest is some movies I converted to play on my long trips on the train. Although not the best way to watch movies, it does kill time quite effectively.