If there is an adequate iTunes-like music player available on Android, DoubleTwist is it. It is an incredibly simple app that lets you keep your personal collection organized, sync to your desktop, subscribe to podcasts, and even listen to live radio. It can also function as a video player, though it is unquestionably best for listening to tunes.
One of DoubleTwist's most important features, AirSync, lets you wirelessly sync your Android music collection with your desktop PC. This feature is only available as a $4.99 upgrade, but considering the convenience it offers, it is well worth it. Another option is the $9.99 DoubleTwist Pro upgrade, which comes with AirSync, plus it gives you a graphic equalizer, useful album art fetcher, and other features. For audiophiles who are serious about their collections, Pro is certainly worth considering.