This is a remarkably interesting and erudite thread containing both mainstream and offbeat suggestions. But reading through it, I did miss two of my favorite recordings.
There are a few recommendations for Nielsen’s music, but nothing praising his Third Symphony which is well deserving of all the praise its fans send its way. Frankly, I think it is a masterpiece, and since there are few recordings available, I may as well recommend the one where I first heard the piece: Leonard Bernstein conducting the Royal Danish Philharmonic Orchestra on a CBS recording released in 1965.
The second of the "missing" recommendations is a very recent recording on the 2L lablel of two song cycles for voice and orchestra by the Norwegian composer Henning Sommerro: Ujamaa and the Iceberg. This might be a little weird for some, but it is tonal, attention grabbing, stunning, and simply the best recording I have ever heard.