CDEx is an application that records audio tracks from CDs and saves them to a disk as regular WAV files or as encoded sound files.And also it converts mp3 to wave,wave to mp3.It is Freeware
Daniusoft MP3 WAV Converter
This is also a good MP3 WAV converter that supports all popular audio formats. This is powerfull application you can convert here mentioned formats: wma, m4a, m4b, aac, wav, mp3, ac3, to mp3, m4a, ac3, aac,wma, wav, ogg, ape.It is also a freeware having good conversion Speed.
Free WAV to MP3 Converter
It is an easy to use free program for converting WAVE files to MP3 files. The program capable of batch process an unlimited list of files, and convert them to MP3 format using good output quality
ABC Amber Audio Converter
It is another freeware to convert wav files to mp3 files (or mp3 files to wav files). ABC Amber Audio Converter is a useful utility supports more than 50 languages .This Utility also capable of batch conversion.