The best audiophile metal/rock albums are the prog ones: Pink Floyd, Symphony X, Opeth, Porcupine Tree, Crimson Glory, Genesis, Neal Morse, Subterranean Masquerade, Maudlin of the Well, Explosions in the Sky, The Gathering, Green Carnation all sound great in a high end headphone. Then there's the audiophile's favorite Dream Theater (not my favorite). The very best audiophile album could very well be Pink Floyd - Dark Side of the Moon.
Other good album would be Mr Bungle - California.