EAC/FLAC = EAC is the best CD Ripper and FLAC is a Loseless Coded.
iTunes ACC M4A = ACC is a Lossy Codec.
FLAC > AAC
If you want to make "Perfect Rips", buy a Plextor Driver and Configure EAC (Windows-only).
You can also try iTunes + ALAC, is Apple's Loseless Codec. FLAC = ALAC.
I made my Rips with EAC + FLAC and then ALAC them for my iPod Video 5G.