In hopes that the request is for "good" music with great recorded sound (rather than good sound only, as found on Sheffield LP’s):
For Baroque era Classical, rushton's 2010 recommendation of the Harmonia Mundi U.S.A. label is a great one. Also, Trevor Pinnock’s harpsichord recordings on the British CRD label. Startling immediacy ("in the room" sound) and transparency. Great playing, too. Then there are the recordings of local Minnesota church choirs made by speaker designer Robert Fulton, released on his ARK label. Very natural sounding, with great inner detail; you can hear each individual voice in the choir.
For Pop, Dan Hicks & His Hot Licks Where’s The Money, Stevie Wonder’s Talking Book, Gordon Lightfoot’s If You Could Read My Mind (particularly "Me & Bobby McGee"), and Paul Simon’s s/t debut album.