Are you asking for real classical stuff? In that case, I'd recommend:
Symphony #9 ("From the New World") by Antonin Dvorak
"Rhapsody on a Theme of Paganini" and Piano Concerto #2 by Sergei Rachmaninov
Pictures at an Exhibition, by Modest Mussorgsky (orchestrated by M. Ravel)
Scheherezade, by Nikolai Rimsky-Korsakov
It depends on what kind of stuff exactly you like to listen to; these are all really great works for symphony orchestra. If you want more chamber music or solo-oriented stuff, I could try to think of some of that, too.
Ah, another good option would be the any of Requiems by Verdi, Mozart, or Brahms.