Rebecca Pidgeon's "Spanish Harlem" is probably a fixture amongst audiophile test tracks, though it's not as well done as I would've imagined a Chesky Records album to be. I have the HDTracks 24/88 Bob Katz remaster.
I also find Vivaldi: Recitative and Aria from Cantata RV 679, "Che giova il sospirar, povero core", which can be found easily on the 2L Nordic Sound high-resolution test bench, a great track that tests out vocal tracking (the singer sways around a lot), bass control (the cellos are quite nice), and transparency, as well as airiness (lots of harpsichord going around).
Actually, the 2L test bench tracks are mostly all pretty well done, and easily accessible by the public, so it'd be a good place to get test tracks. In particular, if you choose any of the tracks with violin in it, I'll probably know it pretty well.
I've got Rebecca Pidgeon's Retrospective album from HDtracks, will be sure to include Spanish Harlem. Got some 2L as well...
I'll see if I can get in first and start you off :-)
Tori Amos or Joss Stone (female vocals)
Tool (contemporary rock/metal)
Led Zeppelin (classic rock)
Phutureprimitive - 'Kinetik' album (heavy sub-bass)
1200 Micrograms (layered synths and electronic drums)
Simon and Garfunkel (male vocals)
Tori Amos: Will be using "Me And A Gun". Brilliant.
Tool: I've got Tool. And A Perfect Circle. And Puscifer. I like Maynard.
Led Zeppelin: I'll have to dig that up
Simon and Garfunkel: Greatest Hits and Parsley, Sage, Rosemary And Thyme are on my shelf.