Just the software you are going to rip with and I have a feeling that will turn into a debate and a half around here!!!!!
From my own experience (I have been doing MP3's since before Napster if that matters!) I have had the best results with EAC and LAME following this standard:
http://www.ubernet.org/modules.php?op=modload&name=Files&file=uberstandard
I must admit that I don't follow that to the letter. I use EAC version V0.95 PreBETA 5 from 8 and LAME 3.96. My results after trying a ton of other combinations, are flawless at 320kps. I have tried them all from Flac to Monkey to a ton of other variations and in the end I have had the best luck and the best results using the above.
