I started to create just a Deluxe edition list like the one I did for Batman but there is much less Superman material so I went ahead and included the omnibus and Absolute editions. Please let me know if I've missed anything. Thanks!
Superman Deluxe Edition/Omnibus/Absolute List
Deluxe Editions: Superman Whatever Happened to the Man of Tomorrow? DLX By Alan Moore Superman vs Muhammad Ali Deluxe by Dennis O'Neil & Neal Adams Superman for All Seasons Deluxe by Loeb and Tim Sale Superman Secret Origin Deluxe by Geoff Johns Superman Unchained: Deluxe edition by Snyder and Jim Lee Superman: Red Son (Deluxe Edition) by Mark Millar Superman: The War Years 1938-1945 by Roy Thomas
Omnibus Editions: Superman: The Golden Age Omnibus volume 1 by Siegel and Shuster Superman: The Golden Age Omnibus volume 2 (2016) Superman: The Death and Return of Superman Omnibus by Dan Jurgens and Karl Kesel
Absolute Editions: Absolute All-Star Superman Absolute Superman: For Tomorrow Absolute Superman/Batman volumes 1 and 2 Absolute Kingdom Come (technically a Superman story)
Superman Deluxe Edition/Omnibus/Absolute List
Deluxe Editions:
Superman Whatever Happened to the Man of Tomorrow? DLX By Alan Moore
Superman vs Muhammad Ali Deluxe by Dennis O'Neil & Neal Adams
Superman for All Seasons Deluxe by Loeb and Tim Sale
Superman Secret Origin Deluxe by Geoff Johns
Superman Unchained: Deluxe edition by Snyder and Jim Lee
Superman: Red Son (Deluxe Edition) by Mark Millar
Superman: The War Years 1938-1945 by Roy Thomas
Omnibus Editions:
Superman: The Golden Age Omnibus volume 1 by Siegel and Shuster
Superman: The Golden Age Omnibus volume 2 (2016)
Superman: The Death and Return of Superman Omnibus by Dan Jurgens and Karl Kesel
Absolute Editions:
Absolute All-Star Superman
Absolute Superman: For Tomorrow
Absolute Superman/Batman volumes 1 and 2
Absolute Kingdom Come (technically a Superman story)