Yeah Classical Mushroom was definitely very intricate/complex, and didn't get boring as long as BPEmpire does. 
  
I forgot to mention the Ozric Tentacles and The Fireman's (Paul McCartney and Youth) 2nd album, Rushes. 
  
Pretty crappy website, but it has a few samples (doesn't do the album justice, though) 
  
-=- Matt/Strumpling -=- 
The Fireman is just as "intelligent" as Shpongle, IMO, and Shpongle's my favorite, so hopefully that means something.