Windows/Mac: There are a plethora of audio converters out there, so why do we need any new ones? Some programs have a steep learning curve and many of the easy-to-use ones aren't free. With MobileHuman's Audio Converter you can click and drag tracks to and from eight popular formats without having to know anything about digital audio.
Once the program is installed all you need do is add audio files to the program's interface, choose what format and bitrate you want to convert the files to, and click ;Start Converting'. The only potentially contentious area is choosing a bitrate, and that defaults to the highest rating automatically so you really don't have to bother with it.
The audio converter can process to and from files in AAC, AIFF, ALAC, FLAC, MP3, OGG, WAV and WMA file formats. If you need to convert files and want something easy to use, give this a try. It's a free download for Windows and Mac OS X from the source link below.