Take a look at
Media Player Classic Black Edition. Install it, run through the settings real quick. Enable MPC Renderer in the audio section and set it for Exclusive Mode. Exit the program.
Now all you have to do is click on a movie or music file in windows explorer and it will pop up and play it for you ... Easy Peasy.
You can also save playlists and when you click them, it pops up to play them from explorer too.
After you use it a bit, you will find you can customize it's behaviour very easily, too...