[Coach G]

Skimming through it seems that no one has yet to mention Dimitri Mitropoulos; one of the few Mahler champions before Leonard Bernstein made it fashionable. The Mitroupoulos/Mahler cycle on the following box set is incomplete (no 2nd, 4th, or DLVDE):

The above set includes an abridged recording of the 3rd that is not as outstanding as the one that Mitroupoulos recorded in Europe shortly before his death:

Mitropoulos' take on Mahler is very sincere, enthusiastic, and free: wonderful; despite the limitations of antiquated sound technology. Given the friendship between Mitropoulos and Bernstein, I often wonder if Mitropoulos, who died in 1961, was the inspiration behind Bernstein's first Mahler cycle.

Dimitri Mitropoulos flanked by Herbert Von Karajan and Leonard Bernstein:

 

[Coach G]

Then there is the Maurice Abravanel who (I think) did the SECOND complete Mahler cycle after Bernstein. Abravanel brought Mahler and old Vienna to the heart of the American West, Mormon country, as the conductor of the second (or third?) rate Utah Symphony Orchestra. Some may call it Mahler on a budget. While not on the same tier as Bernstein/New York, Solti/Chicago, or the many recordings made with the Concertgebouw, or the London, Vienna or Berlin Philharmonic Orchestras; Abravanel and the Utah band can hold their own, playing with great sincerity, and effort; a great Mahler cycle for those who enjoy cheering for the underdog!