These leap immediately to mind though there is really no shortage of candidates. Keep in mind that I am something of a hopeless Romantic when it comes to classical music and Second Viennese School aside can't really get on with the atonal or the plinky plonk. Your tastes might stretch way beyond mine!
John Adams' Transmigration Of Souls - Nonesuch recording
Debussy Pelleas and Melisande Concert Suite - Abbado conducting BPO
Bruckner 4 - Celibidache conducting MPO
Schoenberg Verklarte Nacht - Von Karajan conducting BPO
Brahms German Requiem - Celibidache conducting MPO
Six Marimbas & Music For 18 Musicians - Steve Reich
Bartok String Quartets - Tokyo Quartet
Verdi Overtures - Von Karajan
Bach Cello Suites - Tortelier
Mahler Song of the Earth - Kathleen Ferrier, Bruno Walter etc
Arvo Pärt's Tabula Rasa (ECM Recording)
Arvo Pärt Fratres - Tasmin Little / Martin Roscoe - Richard Studt - Bournemouth Sinfonietta
Britten Peter Grimes Op 33 - Orchestra of the Royal Opera House
Callas Operatic Arias (this was an EMI vinyl single disc from the early 60s, not sure how it has been reissued on CD - probably in a two-fer bundle with another record)
Debussy Symphonic Music La Mer etc - Stokowski & LPO
David Bedford - Twelve Hours Of Sunset
Anton Webern Complete - Boulez
Richard Strauss A Cappella Works - Danish National Radio Choir
Honneger Pastorale D'ete - Jean Fournet & The Netherlands Radio Philharmonic Orchestra