Vorbis

Pros

• Free (as in speech), Open Source and claimed to be patent free
• Good all-round performance (>48 kbps - a leading codec at 128 kbps)
• Well written specs
• Several portable hardware players
• Suitable for internet-streaming (via Icecast and other methods)
• Fully gapless playback
• High potential for further tuning
• Structured to allow the design for a hybrid filterbank.