I love foobar2000.
Fast, low footprint, easy to use, configure and customise. Great ongoing development and support. Mature and helpful community and website. The underlying code is very tight and secure. Did I mention it was free?
What's not to like? Very highly recommended. At least give it a try.
If you are tempted to try something a little more exciting and adventurous consider downloading the free evaluation copy of Ableton Live from their website.
It's the full on pro product except it has a limited number of input and output channels and the reord function is disabled. You are unlikely to want more than stereo I/O if you use it as a highly sophisticated media player and you can even get to save your work by rerouting the output back into an input pair (maybe via S/PDIF) and using free audacity to record.
There is a media library similar to foobar, winamp etc and the quality is superb. The big fun factor comes in the ability to change pitch, add effects and EQ, cut, slice and dice, mix loop and generally lark around to your hearts content. What you can do easily and intuitively is limited only by your imagination.
Another fun application that fits the bill is the free Beatport Sync app you can download if you register with Beatport. It is also pro quality based on the industry standard pro DJ app Traktor from NI. The USP here is that it will effortlessly segue tracks in your various playlists together seamlessly.
