It wasn't so long ago that you could probably identify the top 10
orchestras in the world.  I am not so sure that is the case anymore.
One reason is that the quality of the players has increased everywhere.
It may also be, however, that most of the conductors of the major
orchestras seem to be traffic cops instead of musicians.  I am going to
offer what I believe would have been arguably the top 10 orchestras of
20-15 years ago.  Do you agree with me? What are the top ten today? By the
way, the first five are probably in the correct order, but I am not sure
after that.

1. Berlin Philharmonic
2. Vienna Philharmonic
3. Philadelphia Orchestra
4. New York Philharmonic
5. Chicago Symphony Orchestra
6. Los Angeles Philharmonic
7. London Symphony Orchestra
8. Philharmonia Orchestra
9. London Philharmonic Orchestra
10. The Concertgebouw Orchestra (probably should be in top 10)

Okay, I should probably add the Boston Symphony Orchestra but that would
have been prior to Leinsdorf and the Great Oz.

These orchestras had a rich, deep sound.  They could play anything and play
it well.  Their chief conductors were musicians and when they conducted
they were making music, not just playing it.  They had a "sound".

Peace from he who is stumpf
aka Sisyphus