DoubleTwist's dashboard is pretty straightforward. It lets you sift through your collection by artist, album, song title, or genre. Plus it includes links to streaming radio, a podcast directory, and your playlists.
If your plan is to sync your music between your desktop and mobile device, then the AirSync wireless functionality for $4.99 is a must. The $9.99 Pro upgrade is also worthwhile, as it adds a graphic equalizer, a nifty album art fetcher and other features.