Now, the most popular OT DVD versions out there tend to come from the Def. Collection or Faces LDs.
I've not actually heard the mixes for the Faces versions, and I don't particularly like the Def. Collection versions (with the newly-added sound effects, the lack of 3PO's lines, the missing snowspeeder whine before it crashes, etc.).
The mixes that are near and dear to my heart are the 1985 mixes, featured in my beloved CBS-FOX VHS tapes from 1990 (the first time I ever owned the trilogy).
I'd love it if someone used the sound from the 1992 laserdiscs (which used the 1985 mixes, and are likely the best presentations of the films in that regard).
Still, I'm a stickler for historical accuracy (as are many here), and audio tracks featuring the original mixes (70mm, mono, stereo) would be pretty spiffy, as would the original opening crawl (and other changes rumored to be in the original releases, such as no Chewie scaring mouse droid, alternate "rebel fleet ending" cut for Empire, etc.).