Classical Music for Aficionados

Guys who never wrote a bad note;
Mozart , Schubert, Brahms .

Bach is a given .As are Schumann’s chamber pieces .

Among modern composers Leos Janacek excels in everything .His string quartets are to die for !
If you like long , sweeping symphonies that are just plain beautiful , Sibelius is your man .
Mahler is someone you either like or you don't . No shame either way .

Pete23, As far as showpieces go, the Mahler 6 would be fine if the person whom you are showing has the patience. It is long!!! but never boring. It is my favorite Mahler by far (though I like them all). 

Now if you really want to show off your system I can't think of a better recording than that of Copland's 3d Synphony on the Reference Recording Label. The first piece is Copland's Fanfare for a Common Man. The brass and drums will light your fire for sure. And it is a pretty good version as well.

I don't know the Wood Works you refer to, but if you like Nordic folk music, for something off the beaten path you might try/like Greirr Tveitt's 100 Folk-tunes from Hardanger on BIS. Caveat though, this is not warmed over Greig or Halverson. 

And something rarely mentioned, but which I really enjoy a great deal it movie music by Nino Rota. My first Rota recording was by Muti on the Sony label, which is still my favorite by some margin. It includes an ear worm you just can't resist, Dances from Il Gattopardo.

Lastly, another outstanding piece of music you rarely hear, by another 'Hollywood' composer, Miklos Rozsa. Concerto for Violin and Orchestra. I like the recording on the Koch label but there is an excellent series of this and his other orchestral music on the Chando label. 

Dances from Il Gattopardo.
I see old man Burt Lancaster dancing with beautiful young Claudia Cardinale and jealous Alain Deloit watchinghttps://www.youtube.com/watch?v=qb0IlSBFVt0

@pete23 I strongly recommend Mahler 4 as the gateway drug to Mahler fanaticism.  Thereafter the world's your oyster: 2, 3, 5, 6, 9, 10.  There are passages in all that will test a system.

I agree Mahler 4 is the gateway, but I would posit Symphony 1 as the next step in the quest for Mahler prehension.  And it’s last movement will certainly be a challenge for any system.