What do you all use to play your PC based music collections? I usually have mine on random, but it will eventually play a file from an audio book, or some kids music or something... I realize I could make a playlist including the 1000s of tracks I want and excluding the 100s of tracks I don't... but they're all (or mostly) correctly genre tagged so I'm looking for something that can take 3 or 4 genres (or more!) as an autoplaylist as opposed to song-by-song playlist.

Oh, I'm using Zune currently, by the way.