If disc space is not a problem, what would be the best setting for lame decoder so that i can play back through my HIFi, and when it suits download to 20Gig iPod.
Is there any difference selecting preset insane or 320 CBR. Are these settings the best, could I improve and any other advice. Thank you

Most people here who use MP3, use LAME --alt-preset standard, as it gives transparent sound quality for the majority of people with all music except specific problem samples. I have used this encoder setting personally with tracks I've played back over my PC, portable player, in my car and on my home theater system, and it sounded fine to me on all platforms.

There is a difference between --alt-preset insane and --cbr -b 320, as the alt presets are tuned for relatively better sound quality. However, --alt-preset cbr 320 is exactly the same as --alt-preset insane. When using any alt preset setting, only use the alt preset and don't try tweaking any other options (like lowpass, stereo, etc.) as you might negate some of the advantages you get using just an alt preset.

The FAQ can answer most questions you may have about LAME settings.

On the few lame problem samples I've found (pre-echo mostly), extreme or insane presets had a fairly minor improvement over standard. It has usually been an audible difference though.

I know a better quality setting for files to be put on an iPod:

Nero or Quicktime AAC