I just couldn't limit myself to 30. I came up with 67, which is my age, and therefore seems appropriate. Here they are, not in order of preference but in approximate chronological order--
Haydn 6, 7, 8 (the times of day symphonies), 45, 72, 88, 92, 93, 94, 100, 101, 102.
Mozart 35, 36, 38, 39, 40, 41.
Beethoven 3, 4, 5, 6, 7, 8, 9.
Schubert 4, 5, 6, 8, 9.
Mendelssohn 3, 4, 5.
Schumann 3.
Brahms 1, 4.
Berlioz Symphonie Fantastique.
Franck D Minor Symphony.
Dvorak 5, 6, 7, 8, 9.
Sibelius 1, 2, 5.
Mahler 1, 2, 3, 4, 6, 8, 9.
Bruckner 4.
Tchaikovsky 4, 5, 6.
Prokofiev 1, 5.
Shostakovich 5, 7, 9, 15.
Ives 4.