The best sounding disc I've heard is the Speaker's Corner reissue of Mercury Living Presence Chabrier's Espana on vinyl. I would put psmith's Boulez Mahler 3rd and Kaplan Mahler 2nd SACDs as close seconds to the Mercury.
For Jazz, probably the Analogue Productions SACD of Bill Evans' "Sunday at the Village Vanguard".
For Rock (tough because most rock albums are really compressed), maybe the 30th anniversary DSoTM vinyl reissue.
Other greats:
O Brother Where Art Thou soundtrack on CD or SACD (except for cut one of course)
Manhattan Transfer Extensions on vinyl - the CD sucks!
Joe Jackson's Night and Day on vinyl - same here, the CD reissue was terrible.
Almost anything by Keith Jarrett on ECM.
...many more will come to mind, these are off the top.
Not to start another "what is best" discussion, but a lot depends on one's definition of "good sound". Some people really like compressed music, for example, because it carries more impact. Others go for a natural, you are there sound. There are many more criteria for sound quality.