When I want to evaluate the more "visual" aspects of my system, I alway reach for a live recording. Not that I have anything against tubes and caps that "add" depth and/or width to the perceived soundstage but listening to an actual stage/room is my personal preference.
That said, some of the old warhorses like "Waltz for Debby" or "Jazz at the Pawnshop" are still the lp's that I use. But when it comes to digital I think the choices are less known.
If you have 24/96 playback capabilities from downloaded files, the best I've found is " 4 Generations of Miles" available from HD Tracks. The first cut "There is No Greater Love" is remarkably realistic in it's depth and player/instrument location. At the end of the first sax solo, you can easily hear it as George Colman turns away from the audience and moves from center stage. The drum kit is totally "locked in" as are the sounds of the audience. Some really great music too. I can't say that I've done much listening to it on lesser formats (16/44), but the flac file I have of this recording is excellent!
https://www.hdtracks.com/index.php