Here's the Spotify playlist: EMI: Great Recordings of the Century (201 albums, 4838 tracks) Albums are arranged alphabetically by composer names, except for the Caruso 1902-04 recording which is at the beginning, because it's by various composers, and also the oldest recording in this series. This playlist works better in Album view. Also check out EMI's official page and Amazon for discography and reviews, some of the opera librettos with English translations can be found at EMI's mini site for their Historical series.
Note: Playlists at this size are meant to be references, use the filter bar (Ctrl+F) to find an excellent recording of a composition, or works of a particular composer. Don't try play it from end to end, that would take more than one week of non-stop listening.