I haven't used it yet, just started reworking my music collection. But I will be using this: http://www.tuneupmedia.com/
It looks like it would work for me. The digital fingerprinting would be a big help sorting through songs that are multiple versions of the same songs (acoustic and electric guitar versions of Eric Clapton's Layla). It even looks like it could help with picking the better versions (higher bit rate) of the same recording.I haven't used it yet, just started reworking my music collection. But I will be using this: http://www.tuneupmedia.com/