Apple iPod! By far. There are some outright strange things about the Sony app like not being able to manage a queue of songs easily without creating an adhoc playlist, the navigation is sometimes frustrating, and the default desktop app they provide to sync songs to the player in a manner that will keep lyrics and song art intact is absolutely atrocious. But pretty much everything else is good and there's nothing else on the market so...

I'm quite pleased with my Sony NW-A45. I miss the ability to rate songs, but I understand it is much better than the Android based alternatives.