A few perennial favorites, mostly "early music" played on historical instruments, things I've not seen mentionned heretofore. A few are, sadly, out of print, but when has that stopped anyone ?:
Guillaume Dufay, O Gemma Lux, Complete Isorythmic Motets, Huelgas Ensemble, Paul Van Nevel, Harmonia Mundi
Josquin Desprez, Missa Pange Lingua, Ensemble Organum, Ensemble Clément Janequin, Marcel Pérès, Harmonia Mundi
Claudio Monteverdi, L'Orfeo, Ensemble Elyma, Gabriel Garrido, K617
Henry Purcell, Fantasias for the Viols, Hesperion XX, Jordi Savall, Auvidis
Antoine Forqueray, Pièces de Viole avec la Basse Continue, Paolo Pandolfo, Glossa
François Couperin, Les Nations, Hesperion XX, Jordi Savall, Astrée Auvidis
J-S Bach, Great Organ Works, Gustav Leonhardt, Sony Vivarte
J-S Bach, The Well-Tempered Keyboard, Gustav Leonhardt, Deutsche Harmonia Mundi
Sylvius Leopold Weiss, Pièces de Luth, Hopkinson Smith, Astrée Auvidis
Jean-Philippe Rameau, Les Boréades, Monteverdi Choir, English Baroque Soloists, John Gardiner, Erato
Alban Berg, Wozzeck, Orchestre de l'Opéra de Paris, Pierre Boulez, Sony