There are several obvious Pink Floyd,Beatles and Steely Dan choices, which are almost always reference quality recordings. I will try to recommend a few that are less obvious, but which keep me coming back repeatedly.
Stevie Wonder - Innervisions and/or Talking Book
John Mellencamp - Whenever We wanted. As someone who has played in rock bands 25+ years, this recording does an amazing job of replicating the live sound of individual instruments with lots of definition in space. It also happens to have his best songs.
Soundgarden - Superunknown
The Charlatans - Between 10th and 11th
Wilco - A Ghost is Born
Del Amitri - Twisted
Queens of the Stone Age - R (their first - very dry recording, lots of space, and VERY psychedelic. Not of for everyone, but if you like it, you'll probably love it. My favorite song is sung by Mark Lannegan of Screaming Trees).
Any Supergrass album except "Coco" sounds great on my system. I especially like "In It for the Money" and "Road to Rouen."