Cheap MP3 Player plays music files, supports playlists, uses very little CPU, and it's free.
Here are some key features of "Cheap MP3 Player":
· Low Processor Usage
· Low Level of Features
· Multiple Playlists (that you can't rename)
· Drag & Drop Support
· Plays Music
· Supports any format core audio supports
· Has a repeat button (that may actually look like more than a box someday)
· Create new playlist from the Menu
· No you can't delete playlists
· Awesome Icon
· It works
· Continues playing after it crashes (it will quit after the song is over..)
· No volume control