Mahler, conducted by Pierre Boulez
Wagner, Das Ring der Nibelungen (dir. Patrice Chéreau), Bayreuth Festspiele, P. Boulez
To mark his passing, France Musique has published a multimedia tribute, Boulez à Facettes : de la fulgurance au plaisir, and you can watch a recent long (fascinating) interview with him from the Cité de la Musique (en français). You can also watch the 2015 tribute concert at the Philharmonie de Paris, at which Boulez's beloved ensemble, the Ensemble Intercontemporain, performed his composition Répons, with Matthias Pintscher conducting. The Chicago Symphony Orchestra also has a tribute page, as does the New York Philharmonic.
France Musique has also made available an old live recording of a concert that Boulez conducted in 1981, with the Orchestre National de France and the Choeur de Radio France. In addition to Stravinsky's Le Chant du Rossignol and Schoeberg's Pélleas et Mélisande, soprano Phyllis Bryn Julson is soloist in Boulez's composition Le Soleil des eaux.