I tend to just store MP3 files in folders, and pick and choose what I want to hear. Otherwise I listen to songs on YouTube.
If ever I want to create playlists or store bulk music in a more organized way, I use iTunes. I find it more useful in Mac OSX but the Windows version, like a lot of ported Mac software, feels a little slower and less useful in Windows. Imo Windows Media Player and the default music folder is good enough.