My favorites are the solo piano floppy disks by great jazz artists:
Chick Corea Classics
Teddy Wilson
A Teddy Wilson Encore
George Shearing "Lullaby of Birdland"
Billy Taylor "Healing Hands"
Warren Bernhardt in Concert
Dick Hyman "Blue Skies"
Dick Hyman "Rainy Day Romance"
Andy Laverne "In Walked Bud"
Andy Laverne "By Name Only"
A Steve Allen Interlude
Steve Allen "The things My Heart Tells Me"
Fred Hersch "Virtuoso"
Roger Kellaway "Virtuoso"
Gershwin Plays Gershwin
Jelly Roll Morton "The Piano Rolls"
Oliver Jones "O.J. in L.A."
Jessica Williams "Sentimental Mood"
Don Grusin "Old Friends and Relatives"
David Benoit "Seattle Morning"
Windham Hill Sampler
Also anything by solo classical pianists (too numerous to mention)
But often just as good, if not better, are many of the jazz and classical Plus Audio CDs:
Bob Florence Quartet
The Magic of the Viola
Alan Pasqua "Seasons"
Soprano Arias
Celeste Tavera in Recital
A Sondheim Collection
Sonatas for Cello
Faure, Poulenc and Prokofieff "Music for Flute and Piano"
The Heifetz Encore Trranscriptions
Joey DeFrancesco Concert
The Ayke Agus Trio
Sonatas for Violin
Peter Nero "Live"
Dichterliebe Op.48
Brent Mills "One Step at a Time"
Alan Pasqua "Latin Jazz"
Enchante
Edith Piaf "A Tribute!"
Dave Koz
Free Flight 2001
Ross Tompkins Trio "I Remember You"
Bob Florence "For the Ladies"
Shelly Berg "Hot it Up"
Mike Garson Trio "You Are My Love"
Joyce Valentine and Debbie Brooks "Reunion"
Ray Templin and Ken Treseder "Get Out of Town"
Shubert "Trout Quintet"
John Novello Quartet "Always and Forever"
Best Loved Arias
As others have noted, much more hit and miss are the floppies using the built-in synth sounds. The best feature small jazz groups like the Mike Garson Trio's "Nice and Easy Vol. 1.
The worst (by far) is the Grieg Piano Concerto in A Minor, which has an unlistenable faux-orchestra accompaniment to otherwise worthwhile piano performance by Bryan Pezzone. I'm also not a fan of the Smart disks that superimpose piano noodling on a commercial CD that often is distracting and detracting.
I do think the list price for all of these disks is way out of line. I have been fortunate to find many of them at a discount. It's a shame that many are no longer available. And an even bigger shame that there aren't more disks being recorded by name artists.