audio format converter

[Brian Norman Wootton]

I have about 12 GiB of music tracks and they are a mix of
any audio format you ever heard of. What I would like to do
is convert them  all to one format.  I thought mp3 would be
the most useful, but any better suggestions would be
appreciated.
 I have a 'how to' to do the above but it is console based,
with lots of shell scripts.  I thought that there might be
an X Gui based package which would take the pain out of all
this work, but so far I've googled about with little result.
 Any pointers gratefully received.
brian