1) Check out DCC and other Steve Hoffman releases
2) Check out MoFi (Mobile Fidelity Sound Labs)
3) Talk to LFF
4) Come to the National Meet there will be tons of audiophile music floating around, and you'll get to meet Steve Hoffman!
Some others to check out:
Korn - Unplugged (Be a little cautious with MTV unplugged albums, Korn, Clapton, and Nirvana are awesome! Some others totally suck)
Cantus - Let Your Voice Be Heard
Cantus - Deep River
The Tony Bennett / Bill Evans Album (Fantasy Records)
Infected Mushroom - It's arguable whether or not their stuff could be considered "audiophile" but I find many of their songs to be very good for testing gear, particularly bass and dynamic range.
Diana Krall's Live in Paris album is also quite well recorded. I often use "A Case of You" as a test track.
Marian McPartland's Piano Jazz with Elvis Costello is strikingly well recorded. Elvis sounds surprisingly good singing jazz... I think he missed his real calling. <shrug> He did marry Diana Krall...
Jacintha ...can't really pick a standout, it's all amazing.
Jane Monheit is a little hit and miss, but some of the recordings are phenomenal... Over the Rainbow on Come Dream with Me is staggering.
Maybe not quite audiophile, but well recorded and worth checking out would be Norah Jones with the Peter Malik Group and The Little Willies
Rebecca Pidgeon's Retrospective is generally pretty well regarded for recording quality and her version of Spanish Harlem is on I believe it's Chesky's test disc.
Limon (Talk to LFF)
Not quite audiophile but very close would be Dixie Chicks - Home. Although, track 11 "Godspeed" pushes into audiophile territory IMHO.
Many Telarc recordings are also quite good