Just for giggles and kicks, and out of curiosity, I asked Alex Ross, one of the New Yorker's music critics, for his favorite symphonies by number. So for each number from 1 through 9, which composer's symphony of that number was his favorite? He responded with the following:
No. 1: Nielsen [1]
No. 2: Stravinsky (Symphony of Psalms)
No. 3: Beethoven (Lutoslawski close runner-up)
No. 4: Shostakovich
No. 5: Sibelius
No. 6: Vaughan Williams
No. 7: Mahler
No. 8: Dvorak
No. 9: Schubert [2]
That's a great list that includes five symphonies I have yet to hear. If I have time later this week I'll try and link to some great recordings of each.
Ross has a great weblog for music fans, especially classical music buffs, called The Rest Is Noise. Here's Ross's best of the year in music lists. Here's another Best of 2005 list, courtesy of Ross's fellow New Yorker music critic Sasha Frère-Jønes. And, while I'm at it, Pitchfork's Top 50 Albums of 2005.
[1] Bruckner wrote a Symphony No. 0, the "Nullte". It was published posthumously and was likely actually the second symphony Bruckner wrote, though he shelved it.
[2] Beyond No. 9, only a few composers are left in the running (Shostakovich through No. 15, and Mozart and Haydn beyond that).