The OP made a distinction when mentioning scores re-recorded BY THE COMPOSER for an album release. Most of the scores I've unfortunately been duped into buying that were far removed from the original were arranged or conducted by someone other than the composer. Elmer Bernsteins's TRUE GRIT, arranged and conducted by Artie Butler; Jerry Goldsmith's WARNING SHOT, arranged and conducted by Si Zentner; Ennio Morricone's FOR A FEW DOLLARS MORE, arranged and conducted by Hugo Montenegro are just a few notable examples. The Morricone was the only version available in the US for many years (unless you sprung for an imported copy...much more difficult in the pre-internet years). These versions were often jazzed-up or otherwise calibrated for easy-listening and were, regardless of one's opinion of the musical quality, far from representative of the score. Needless to say, they got almost no play from me after the original versions finally came out...often decades later.
Most of the scores I've unfortunately been duped into buying that were far removed from the original were arranged or conducted by someone other than the composer.
For me the worst offender was Blade Runner. What were they thinking? Vangelis was huge after Chariots of Fire -- so of course Warners. goes and commissions a Blade Runner "adaptation" that sounded nothing like Vangelis.
And the sad part is, they could have hired Mike Lang, Ralph Grierson and Emil Richards and locked them in a room with Vangelis' BR tapes for a week with the orders "duplicate this", and it would have sounded great.
Schifrin recorded BULLIT even three times. The original film score tracks and the original soundtrack album tracks, both of which were released on one CD on FSM. Then he recorded both album takes and film takes again for a new album in 2000 for his own Aleph label. I like all three BULLIT albums. :-)
I just recently got the Aleph recording. Great stuff. Even has a unique track in the guitar arrangement of the main theme.
But the FSM album is easily in my one of my favorite 'OST + album' releases too.
Scores where the re-recorded album version is absolute indispensable for me: The Fury, Damien Omen II, Capricorn One, Jaws.
Very honorable mention to Herrmann’s Phase 4 revisits of his own scores later in his career, which was the first time I encountered most of those scores on LP.
So lots of original scores have been rerecorded for a more proper listening experience by the composer.Which ones are most different from the original recordings.... Like eg. Schifrin's BULLITT
CAPRICORN ONE and MASADA are great examples- I prefer their re-recordings which expand the orchestra size. Also JUSTINE and THE WILD ROVERS have a great re-recordings to vouch for.