If I remember correctly, there's the 1980 original, the 85 remix (which isn't different content wise from the 80 mix, just sonically adjusted for homevideo), the 93 remix which is missing a landspeeder crash sound (I think...?) and finally hairy hen's 5.1 purist mix which I believe is the 93 mix with a few fixes to make it more like the 80 mix and a discreet channel added.

There's also a mix hairy hen did in which he changed a few cues to make them sound better. This is not a purist mix, but him fixing things that bothered him in the original mix.

My vote might be for the purist mix... A nice surround sound mix. Don't know how easy it would be to edit multi track audio...