the dvd-audio of King Crimson's In the Court of the Crimson King. WOW! OK, you need to know that the surround sound mix is not killer. At all. It is barely surround sound.
But the 24 bit 96kHz remixes are fantastic! Lots of snappy treble, the textures of the voices are great, and I learned that some of what I thought was guitar was woodwinds and vice versa.
On top of that, there are various mixes and some extended versions.
If you enjoy this type of thing, you need this disc, it so rocks.