I would have built an encyclopedic collection which I did, but on thrift store vinyl.

As it is, for $30.99 (lots of extracts from multi-volume works here):

HAUL

• J.S. Bach - Complete Cantatas, Vol. VI (BWV 76, 75, 190, 179, 59, 69, 50, 186, 104, 69a)
  Soloists, Amsterdam Baroque Orchestra/Ton Koopman (Erato D225470) (1997)
  Looking at this there are several repeats, which is an encouraging thing when you’re building a cantata collection piecemeal
• J.S. Bach - Cantatas, Vol. 13 (BWV 1, 62, 96, 38, 93, 33, 133, 122, 92)(Erato CC772215) (2000)
• J.S. Bach - Cantatas, Vol. 14 (BWV 68, 6, 74, 126, 26, 125, 178, Konzertsatz BWV 1045, BWV 103, 42, 123) (Erato CC772265) (2000)
  Soloists, Amsterdam Baroque Orchestra/Ton Koopman
  Fewer if any repeats on these two volumes. I guess by the time of volume 14 you’re getting to the bottom of the barrel. The Bach cantatas can fit on what, twenty discs?
• J.S. Bach - The Great Organ Works (Naxos 8.553859) (1992-93)
  Wolfgang Rübsam or Bertalan Hock
  Finally, the organ greatest-hits album that are so numerous on vinyl. The D-minor toccata and fugue, a standalone fugue, a prelude and fugue (“St. Anne”), two chorale preludes, the toccata, adagio, and fugue; and the passacaglia and fugue. Perfect one-CD greatest hits.
• J.S. Bach - Orgelwerke, Vol. 2 (Novalis 150 020-2) (1987)
• J.S. Bach - Orgelwerke, Vol. 3 (Novalis 150 036-2) (1988)
• J.S. Bach - Orgelwerke, Vol. 4 (Novalis 150 052-2) (1988)
  Ton Koopman
  Presumably volume one is in a different bin. These are structured as proper albums, with something like a couple preludes and fugues, a few chorale preludes, a trio sonata, and whatever miscellaneous pieces. This seems like a cracking way to become acquainted with these great works.
• Bartók - Violin Concertos 1 & 2 (Sony SK 48941) (1990)
  Midori; Berlin Philharmonic/Zubin Mehta
  Forgive me for doubting if a young teen or preteen is capable of grasping and handling Bartók’s heart. Still, it’s repertory I don’t have on CD, for about a buck – and in the case of the first concerto, at all.
• Bax - “Spring Fire” symphony, Symphonic Scherzo, Northern Ballad No. 2 (Chandos CHAN 8464) (1986)
  Royal Philharmonic Orchestra/Vernon Handley
• Bax - Piano Music, Vol. III (Chandos CHAN 8732) (1990)
  Eric Parkin
• Berlioz - Messe solenne (Philips D 102949) (1994)
  Monteverdi Choir; Orchestre Révolutionaire et Romantique/John Eliot Gardiner
  The first recorded performance. Either a new discovery or it somehow slipped the attention of Colin Davis’ ’60s cycle.
• Lord Berners - The Triumph of Neptune, L’Uomo dai Baffi, Valses bourgeoises, Polka (Naxos 8.223711) (1996)
  English Northern Philharmonia/David Lloyd-Jones
  Ballet music from a composer I know literally nothing about except what’s on the label. Englishman, contemporary of Elgar, obviously well-born and expectedly conservative. We’ll see.
• Clementi - Piano Music: Capriccio No. 1, Sonata Op. 40 No. 3, Capriccio No. 4, Monferrinas (Hänssler CD 93.096) (2002)
  Lilya Züberstein
  contemporary of Beethoven
• Halvorsen - Symphony 2, Norske Eventybilleder, etc.
  Terie Tamnesem (vn), Oslo Philharmonic Orchestra/Karsten Andersen
  A Norwegian contemporary of Sibelius
• Ives - Piano Sonata No. 2, “Concord, Mass. 1840-60” (Elektra Nonesuch 9 71337-2) (1977)
  Gilbert Kalisch
  It is said that the Concord sonata is among the most difficult performable works and that every interpretation really by definition is unique. We’ll see.
• Mozart - Vespers, Ave verum corpus (EMI CDC 7-49672-2) (1982)
  The Hilliard Ensemble, Choir of King’s College, Cambridge/Stephen Cleobury
• Paganini - Violin Concerto No. 1; Spohr - Violin Concerto No. 5 (Deutsche Grammophon B0007188-02) (2006)
  Hilary Hahn; Swedish Radio Symphony Orchestra/Eiji Oue
  Isn’t it sad that budgets these days are such that you have to choose between a top-flight soloist or an all-star conductor and orchestra?
• Ravel - Piano Concertos; Honegger, Françaix - Concertinos) (London 452 448-2) (1996)
  Jean-Yves Thibaudet; Orchestre symphonique de Monteéal/Charles Duroit
• Schubert - Symphonies 3, 5, 6 (EMI Studio CDM 7 69750 2) (1956, 1960)
  Royal Philharmonic Orchestra/Sir Thomas Beecham
  A real blast to the past for me. I had this CD and sold it in hard times but I always particularly liked it, and now it’s back.
• Scriabin, Prokofiev, Shostakovich - Various short piano works (Philips 438 627-2) (given as 1994 with no information about the recording. Boo!)
  Sviatoslav Richter
• Schumann - Papillons, Davidsbündlertanze (EMI 5 65464 2) (1978)
  Christian Zacharias
  The recording date is given 1978 but I have no traces of Zacharias in my collection, CD, digital media files, or vinyl. That’s unusual. There’s probably a good reason why I’d never heard of him.
• Schumann - Piano Concerto, Carnaval, etc. (Pearl GEMM CD 9463)
  Dame Myra Hess: orchestra/Walter Goehr
• Mark-Anthony Turnage - Drowned Out, Momentum, Kai, Three Screaming Popes (EMI British Composers 5.55091 2) (1992, 1994)
  City of Birmingham Symphony Orchestra/Simon Rattle
  *Pre-knighthood for Sir Simon. Turnage is a particularly contemporary composer, born 1960, and I know literally nothing about him. I look forward to this one.
• Vivaldi, Handel, Telemann, C.P.E. Bach - Oboe Sonatas (Philips 422 070-2) (1989)
  Heinz Holliger (ob), Christiane Jaccottet (hpd), Thomas Demenga (vc)
  (Various) - An Irish Rhapsody (Chandos Collect CHAN 6525) (1979, 1981, 1986-89)
  The Ulster Orchestra/Bryden Thomson and Vernon Handley
  A collection of music by Irish contemporaries of Bax and Vaughan Williams, conducted by two titans of British music because we all know, deep down, that the deepest wish of the Irish is to become British. Haha, I’m 0% Irish according to Ancestry. Majority English, Wesh, and Scottish.*

…

• Handel - Deidamia (Virgin Veritas 5 45669 2) (2003)
  Soloists; Il Complesso Barocco/Alan Curtis)
  Handel operas, like Bach cantatas, are an endlessly rewarding subgenre in themselves.)
• Mozart - La Clemenza di Tito (Teldec 4509-90857-2) (1995)
  Soloists; Chor und Orchester der Oper Zürich/Nikolaus Harnoncourt
  The last mature opera I had yet to ever buy, let alone to hear. Even if it sucks it’s new Mozart more substantial than violin sonatas and divertimenti.