Note: iSonics is not being sold anymore and is listed only for people who had purchased it in the past.

iSonics makes it easy to convert any audio format and CDs to all popular audio formats: MP3, MP2, AAC, FLAC, ALAC, WMA, OGG Vorbis, AC3, and WAV.

It handles metadata with ease and even enables you to change metadata.

As a bonus you can import CDs and convert the audio tracks to any audio format, including metadata retrieved online.