If you consider yourself a geek, you might want to use foobar2000: http://www.foobar2000.org/
This is hands down the best Media Player available on Windows. It doesn't look very good, but it's 100% customizable. It's got towns of 'components' (add-ons), for instance a UPnP client or Last.fm scrobbler. It's also the only Media Player on Windows able to play using ASIO drivers (for Bit Perfect streaming to a DAc - I did say this is for geek), so if you're into actual Hifi, you want that.
It supports every single audio format known to mankind, it's open source, it's light, and it parses my 50,000+ library, over the network, in about 2 minutes. Even Winamp's media library parsing wasn't as fast as this one.
Hopefully, with the death of Winamp, foobar2000 will pick up more user base and some people will develop nice skins, so users are not pushed away by the looks of the software - again, it looks ugly, but feature-wise it's the most complete media player hands down. I love the way you can customize it to fit your exact needs.
No, I don't participate to the project I just like it very much.