A 1990 CD by the Music & Arts label called Glenn Gould - Previously Unreleased Performances of Works by J.S. Bach, 1957-1969.
This is a tough CD to find. I lucked out. It’s on YouTube. There’s also a live performance on YouTube of his unbelievable performance/conducting of Cantata No. 54.
It’s a favorite because it’s so hard to find, is not available in any media other than YouTube and contains such incredible music.
There is a version of the Soundtrack to David Lynch’s Mulholland Drive on multiple formats (the vinyl pressing goes for $400-$700 presently on Discogs) but the CD is great if for the sole reason it a) doesn’t cost $500, and b) has Rebekah Del Rio’s performance of “Llorando” (an a cappella Spanish version of Roy Orbison’s ‘Crying’) which may be the greatest vocal performance I’ve ever heard.