My favorite ones are early John Butcher solo records - "13 Friendly Numbers", "Invisible Ear" and "Fixations (14)". These are the solo saxophone records I return to most often.
I don't like solo Lacy that much, I definitely prefer Lol Coxhill when it comes to soprano saxophone. With Lacy I get a feeling that rhythm section is missing - particularly when he plays Monk tunes. With Coxhill it's all harmoniously complete.
One excellent solo record that I think was not mentioned is Mototeru Takagi "Love Dance". This is some really lyrical stuff.
https://www.discogs.com/release/22195261-高木元輝-Love-Dance-Solo-Live-At-Galerie-De-Café-伝-Tokyo-1987-1997
And Ellery Eskelin has a very nice solo record:
Too bad the Ed Blackwell LP on Sweet Earth never got released. Maybe there's a chance some intrepid label will put the tapes out on CD...
Great photo of Marion, by the way.
In addition see thread “The art of the solo on wind instruments”, 2015 -17! https://www.organissimo.org/forum/topic/77288-the-art-of-the-solo-on-wind-instruments/ Unfortunately, not all scans are available anymore.