There are a few surprising omissions in my opinion:
Prokofiev Peter and the Wolf
Verdi Otello
Holst The Planets
Rimsky-K: Scheherezade
If it is any consolation, I finally decided on my two discs after several days of agonizing, while in the shower this morning, and then checked this thread to see the game is over

but at least, without consulting the thread, I chose to include one of those four works!!
Rimsky-Korsakov: Scheherazade / Scriabin: La poeme d'extase. LSO, Evgeny Svetlanov (BBC Legends)
Gershwin by Grofe: Rhapsody in Blue, I Got Rhythm, etc. Lincoln Mayorga, Al Gallodoro, Harmonie Ensemble (harmonia mundi)