WMP actually isn't that bad these days, though all I use it for is ripping CDs (yep, those shiny plastic things for you young'uns) since it's great at that. For playback in Windows, I've stuck with Winamp through the years as I haven't found anything that works the way it does without a bunch of features I don't need. I tried Foobar2000 and couldn't get into it, and MediaMonkey just seemed like overkill.

By the way, a great site for finding apps in specific genres is alternativeto.net. Here's a list of alternatives to iTunes:

http://alternativeto.net/software/itunes/?platform=windows