Mrs. Miniver (1942)

The MGM LaserDisc sounds slightly better than the Warner DVD and blu-ray, which are identical. The high frequencies don't differ much, but the mids do - there's quite a lot of ambient sound in the midrange that has been strongly attenuated in the newer track.

The blu-ray DTS-HD MA is a lossy transcode. (Again, not that anyone ever noticed or ever would have~)