My main media player is Windows 7's good old Windows Media Player, recently I found my iPod Nano while going through some of my stuff, so I ended up installing iTunes on my PC so I could put some new music on my iPod, since I tend to make my music using audio loops, I use a bit of software called Ableton Live, occasionally when I want to make my own audio loops I'll use Audacity to record and edit audio....pretty good bit of software considering that it's free.