I have been looking too. First I bought a Kindle Fire and when I learned that I could not play one song, then have it stop, I was annoyed. I called c/s and they said the only work around was to place each song into its own playlist! Each of my hundreds of songs! I sold the KF on eBay.
Now I find that the Nexus 10 does the same thing. I have tried every player out there and none of them have a lick of common sense. Who came up with that idea? To NOT be able to play one song and stop?
Oh, one does. itunes lets us play one song, then stop. So, Google, what's up with that? Developers? Anybody? Hellooooo??