Groove: Smart Music Player - Groove is a music player which helps you rediscover your music in new, interesting ways. It studies your listening habits and creates a wide variety of instant mixes like your own personal DJ. You will never have to manually create a playlist again.
With Groove, listening in the car is easier too
iSub is an iPhone and iPod Touch client for the popular open source Subsonic music streaming software (subsonic.org). Stream your personal music collection from your home computer to your device regardless of format. Subsonic will automatically transcode most file formats, and can even lower the bitrate to save bandwidth
Plex (iPhone/iPad) - The Plex application allows you to use your iPhone, iPod touch or iPad to browse and play your media (video, photos and music) using the Plex Media Server installed on your Mac. In addition, you can view online media from a variety of sources. If you have Aperture, iPhoto, or iTunes installed you can also stream the content to your mobile device
Z-Subsonic streams your entire music collection (WMA, FLAC, MP3, AAC, OGG and more) securely to your iPhone/iPod/iPad without going through a third-party server.
Z-Subsonic is a client to the popular Subsonic open-source music streaming server. Z-Subsonic requires Subsonic server. Subsonic server can be found at subsonic.org
APE Music Player - APE Music Player is an audio player for people who want to listen to music in high quality. The app supports the APE lossless audio format, as well as the classic MP3 format.
APE Music Player lets you play your music by folders or playlists. Audio files can be transferred via WiFi and USB