What do you think are the best recordings available of Mahler's 9th Symphony?

I have been looking at three recordings by Bernstein, and one by Boulez. Which would you buy? And are there others worthy of consideration?

What do you think are the best recordings available of Mahler's 9th Symphony?chicago theater

Those are good selections, especially the Bernstein (he did two, the latter one with the Vienna, former with NY phil) I recommend Karajan's second effort (recorded live) with the Berlin Phil. It is as good as any, certainly the rival to Bernstein.

What do you think are the best recordings available of Mahler's 9th Symphony?met opera opera theater

My favourite is an old recording from 1938 with the Vienna Philharmonic conducted by Bruno Walter. It is a live performance. Walter worked with Mahler in mahler's last years and conducted the first ever performance of the 9th. This an old remastered mono wax disc recording, not a digital 'perfect balance and sound' recording. The playing is not always perfect. But it is so full of passion and emotion, something that is frequently missing in modern recordings. It was available on an EMI CD, CDH 7 63029 2. If you can find it give it a listen you won't regret it.
Fortunately this masterpiece has several great recordings.

My favourite is Carlo Maria Giulini with the Chicago Symphony.

The old version of Bruno Walter with the Vienna Philarmonic (1938) is a landmark, but the sound is very poor. Walter recorded it again with the Columbia Symphony.

Then you have the second recording (live) Herbert von Karajan made with the Berlin Philarminic; same orchestra with Sir John Barbirolli and Otto Klemperer with the New Philarmonia Orchestra.