Elgar's fantastic. It's too bad he's mostly known for Pomp and Circumstance.
My favorite piano concerto is
Grieg's Piano Concerto in A Minor. The opening movement makes my heart ache every time I hear it (literally).
The second movement of Dvorak's New World Symphony features an astoundingly beautiful English horn solo.
I used to hate
Mussorgsky's Pictures at an Exhibition. Because of its difficulty, it was almost mandatory in any sort of orchestra audition. It's referred to as "Pictures that are extra bitchin'" by musicians. Now I can't get enough of it.
No time to post more tonight, but when I'm free again, I'll put in Brahms's Hungarian Dances, Dvorak's Slavonic Dances, Stravinsky's The Firebird, and more.
I'll also take a look through my collection for more obscure stuff.