My non-objective list of 10 Epic Moments In Classical Music.
1. W.A. Mozart: Don Giovanni. 1787.
2. Shostakovich: Symphony No. 8 :III. Movement. 1943.
3. Tchaikovsky: Iolanta. 1892.
4. Scöenberg: Gurre-Lieder. 1911.
5. Stravinsky: Le Sacre du printemps. 1913.
6. Messiaen: Turangalîla-Symphonie. 1949.
7. Britten: War Requiem. 1962.
8. Rachmaninoff: Rhapsody on a Theme of Paganini. 1934.
9. Poulenc: Stabat Mater. 1951
10. Bartók: Bluebeards Castle. 1918.
source
Also try more non modern classicals
Honestly Britten War Requiem is so underrated, absolute game changer!
link to the mozart?