Oops, I myself forgot to mention the stunning Schumann symphony cycle
conducted by Swallisch, especially the second.  Also, the Gurrelieder
conducted by Sinopoli (conducting a bit odd at points but the transparacy
of the orchestral sound made me aware of the colours and beauty of this
work.  Sensational recorded sound)

I second the RCA Navigator Brahms/Sanderling symphony recommendation of
Dave Lampson, especially the 3rd and 4th symphonies.

Overall, though, I'd choose the Strauss Denon CDs(perhaps alongside the
Schuman 2nd mentioned above) as proof of what this orchestra can do.
Especially as these Denon discs are amongst the finest sonically that
I have ever heard.

Happy listening,

David Harbin
Nottingham, UK