Here are my favorite pieces (and performances, where noted)

BACH, Johann Sebastian (1685-1750) 
  ORCHESTRAL
* Brandenburg Concerto #5 
    by Trevor Pinnock 

  SOLO 
* Goldberg Variations 
    by Glenn Gloud, 1955 recording

  ORGAN MUSIC
* Passacaglia and Fugue in C Minor

  MISCELLANEOUS
* "Bist du bei mir" from the Anna Magdalena Notebook

BARTOK, Bela (1881-1945)
* Concerto for Orchestra
    by Fritz Reiner

BEETHOVEN, Ludwig van (1770-1827) 
  SOLO INSTRUMENT (tie)
* Piano Sonata #27, op. 90
    by Charles Rosen
* Piano Sonata #30, op. 109
    by Solomon

  DUO 
* Violin Sonata #7 in C Minor, op. 30, no. 2
    by Itzhak Perlman and Vladimir Ashkenazy

  TRIO
* "Archduke" Piano Trio, op. 97

  QUARTET
* String Quartet in C-sharp Minor, op. 131

  CONCERTO 
* Piano Concerto #4 in G

  SYMPHONY (tie)
* Symphony #7 
    by Carlos Kleiber
* Symphony #9
    by Wilhelm Furtwangler, 1942 Berlin and 1951 Bayreuth

BERLIOZ, Hector (1803-1869)
* Symphonie Fantastique
    by Sir Colin Davis

BRAHMS, Johannes (1833-1897) 
  CONCERTO (tie)
* Piano Concerto #2 
    by Sviatoslav Richter and Erich Leinsdorf
* Violin Concerto in D
    by Jascha Heifetz and Fritz Reiner

  SOLO
* Intermezzi op. 117-119
    by Radu Lupu

  DUO
* Cello Sonata #1 in E Minor

  TRIO
* Piano Trio in B Major, op. 8

  QUARTET
* Piano Quartet in C Minor, op. 60
    by Artur Rubinstein and the Guarneri Quartet

  QUINTET
* Piano Quintet, op. 34
    by Jeno Jando and the Kodaly Quartet

  SEXTET
* String Sextet "Agathe", op. 36

  CHORAL
* Ein Deutsches Requiem 
    by Otto Klemperer 

  SYMPHONY
* Symphony #4
    by Otto Klemperer 
  
BRUCKNER, Anton (1824-1896) 
* Symphony #8, "Apocalyptic"

CHOPIN, Frederic (1810-1849) 
  SOLO (tie)
* Nocturnes 
    by Artur Rubinstein *and* Ivan Moravec

CORELLI, Archangelo (1653-1713) 
* Concerti Grossi (Op. 6) 
    by Trevor Pinnock 

DVORAK, Antonin (1841-1904) 
* Symphony #9, "From the New World"
    by Rafael Kubelik 

ELGAR, Edward (1857-1934)
* Enigma Variations
    by Sir Adrian Boult

FAURE, Gabriel (1845-1924) 
* Requiem

GRIEG, Edvard (1843-1907) 
* Piano Concerto in A, op. 16

HANDEL, George Frederic (1685-1759) 
  SOLO
* the Eight Great Harpsichord Suites

  ORCHESTRAL
* Water Music

HAYDN, Joseph (1732-1809) 
  SYMPHONY (tie)
* Symphony #82, "the Bear"
    by Leonard Bernstein
* Symphony #102

MAHLER, Gustav (1860-1911) 
  SYMPHONY (tie)
* Symphony #2 "Resurrection"
    by Otto Klemperer 
* Symphony #6 "Tragic"

  SONG CYCLE
* Songs of a Wayfarer

MENDELSSOHN, Felix (1809-1847) 
  SOLO 
* Variations Serieuses, op. 54

  TRIO
* Piano Trio #1

  CONCERTO
* Violin Concerto in E Minor
 
  SYMPHONY
* Symphony #3 in A, "Scottish"
    by Peter Maag

MOZART, Wolfgang Amadeus (1756-1791) 
  CONCERTO
* Piano Concerto #23 in A
    by Malcolm Bilson and John Eliot Gardiner

  SOLO
* Piano Sonata, K. 333
    by Walter Klien

  DUO
* Piano Sonata for Four Hands, K. 448 
    by Radu Lupu and Murray Perahia 

  CHORAL
* Requiem, K. 626 
    by John Eliot Gardiner

  SYMPHONY
* Symphony #38, "Prague"

MUSSORGSKY, Modest (1839-1881) 
* Pictures at an Exhibition (piano)
    by Sviatoslav Richter 

PROKOFIEV, Sergei (1891-1953) 
* Symphony #1, "Classical"

RACHMANINOFF, Sergei (1873-1943) 
* Piano Concerto #2
    by Byron Janis

RAVEL, Maurice (1875-1937) 
* Pavane for a Dead Princess
    by Fritz Reiner

RIMSKY-KORSAKOV, Nikolai (1844-1908) 
* Scheherazade 
    by Sir Charles Mackerras

SAINT-SAENS, Camille (1835-1921) 
* Piano Concerto #2 
    by Artur Rubinstein 

SCHUBERT, Franz (1797-1828) 
  SONG CYCLE
* Die Schone Mullerin 
    by Ian Bostridge and Graham Johnson 

  SOLO (tie)
* Piano Sonata in G, D. 894
    by Radu Lupu
* "Wanderer" Fantasy
    by Sviatoslav Richter

  QUARTET
* String Quartet in A Minor, "Death and the Maiden", D. 810

  QUINTET
* String Quintet in C, D. 956 
  
  SYMPHONY
* Symphony #8, "Unfinished"
  
SCHUMANN, Robert (1810-1856) 
  QUINTET
* Piano Quintet
    by Jeno Jando and the Kodaly Quartet

  SOLO
* Fantasy in C 
    by Sviatoslav Richter

  SYMPHONY
* Symphony #4 
    by Rafael Kubelik

SIBELIUS, Jean (1865-1957) 
  CONCERTO
* Violin Concerto in D

  SYMPHONY
* Symphony #2

  SYMPHONIC POEM
* The Swan of Tuonela

SMETANA, Bedrich (March 1824-1884) 
* The Moldau, from "Ma Vlast"
    by George Szell 

STRAVINSKY, Igor (1882-1971) 
* Firebird Suite 

TCHAIKOVSKY, Peter Ilyich (1840-1893) 
  QUARTET
* String Quartet #1, op. 11
    by the Hollywood String Quartet

  SYMPHONY
* Symphony #6, "Pathetique"
    by Carlo Maria Giulini

  TONE POEM
* Romeo and Juliet
    by Sir George Solti  

WAGNER, Richard (1813-1883) 
* Prelude and Liebestod from "Tristan und Isolde" 
    by George Szell