I also can’t just have one per category so I’ve listed those that I think are works of the first rank. I also have listed what I think is a recording of the first rank for each.
1. Composer: Beethoven, Bach, Mozart, Haydn, Monteverdi, Bartok.
2. Symphony: Beethoven 3 (Toscanini 1938), Beethoven 9 (Furtwangler Lucerne), Beethoven 5 (Kleiber), Bruckner 8 (Karajan/Vienna), Haydn 88 (Bruggen), Beethoven 7 (Kleiber), Mozart 41 (Toscanini), Brahms 4 (Kleiber), Brahms 1 (Karajan).
3. Opera: Marriage of Figaro (Kleiber), The Ring (Solti).
4. Bach Mass: in Bm (Richter), Monteverdi Vespers (Munrow), Missa Solemnis (Gardiner).
5. Piano Concerto: Beethoven 4 (Fleischer), Mozart 27 (Perahia).
6. String Quartet: Beethoven Op 130, 135 (Italiano), Haydn Op 76 (Lindsay), Bartok 5 (Tokyo), Mozart “Haydn” Quartets (Italiano), Ravel (Italiano).
7. Overture: Marriage of Figaro (Kleiber), Freischutz(Kleiber).
8. Piano Sonata Beethoven 29 (Brendel), 23, 21, 14, 8 (Schnabel or Brendel), Liszt Bm (Argerich).
9. Tone Poem: Berlioz Symphonie Fantastique (Gardner), Strauss Zarathustra (Reiner 1954).
10. Violin Concerto: Brahms (Heifitz or Vengerov), Beethoven (Heifitz).
Plus Bach is way under represented because of the categories chosen. Works by him that belong in this august company are Art of the Fugue (Walcha), Tocatta and Fugue in Dm (Koopman), Violn sonatas and partitas (Milstein), Cello Sonatas (Casals), The Well Tempered Clavier (Gould)