Lessee ... this is a first pass, not in any order, and not necessarily my penultimate list IMNSHO:

Radiohead: OK Computer
Tori Amos: Little Earthquakes
Bjork: Post
Tool: Lateralus
Frank Zappa: Lather
Rush: Exit ... Stage Left
Kevin Gilbert: Thud
Mike Keneally: hat.
Solti: The Planets
Chess (London Original Cast Recording)