I just bought the Lee Konitz duets volume of Music Minus One. This is the first MMO volume that I've bought, though I've seen them in stores for decades. The Konitz volume has some tracks that are just sax duets and a few that are large groups with solo sax (with or without Lee's part).
This is the bright idea that made Jamey a wealthy man. After practicing with Aebersolds for many years it was a nice change to play with a MMO. The MMOs have elaborate large ensemble arrangements and they're recorded extremely well. There are a some very cool looking MMO volumes, such as the Zoot Sims sax duets, the piano trio volume and the lead alto big band volume.
I'm definitely going to pick up a few more of these myself.
Lee Konitz Somewhere Sax Duet PDF