LAME is a free world-class MP3 encoder, on par with Fraunhofer best ones (the reference in the matter with mp3enc 3.1), with the addition of an excellent VBR support. It's usually distributed only in source code format, but I found a Win9x/NT compiled version of the latest version at MP3'Tech or Dmitry's page. LAME has a command-line interface only, but you might be able to use it in conjunction with your favorite CD ripper, or with this nice front-end GUI.
