High fidelity recordings (if it's 1957)
It goes without saying, or at least it should, that audiophiles are weird.
Seriously. Go, at your first convenience (i.e., after finishing this post), and check out some of the major audiophile message boards. Did you know that a well-nigh unavailable West German pressing from 1985 of your favorite record is, hands down, the best nunc et semper et in saecula saeculorum. Well, it is. So we're told. There's also a progression from the latest original-engineer remasters being the best to the ones from ten years ago to the ones from Japan to the ones from West Germany (If the MFSL/DCC issue from 1992 isn't the best). Or some such similar progression.
While I am certainly no fan of over-compressed, super-bright, and painfully loud recordings or botches passing themselves off as remasters, I am forced to say that, for 80% of music out there, it doesn't really matter. The Mobile Fidelity release of Who Are You by The Who (UDCD 561, June 1992) might be the best release of that record - and there is some debate - but that's not saying much. (I should note that "Sister Disco," "Trick of the Light," and the eponymous track are pretty enjoyable, but that's neither here nor there.) Releases such as this are, more or less, triage operations: they'll make the records sound as good as they can for people who care.
The two areas of music, however, where audiophile standards matter are, of course, jazz and serious art-music (i.e., classical). Scott La Faro's work with Bill Evans at the Village Vanguard in 1961 (Sunday at the Village Vanguard) should sound good. So should, for that matter, Pierre Fournier's traversal of the Bach cello suites. In the case of 'classical,' the dynamic range and various orchestral - and human - voices require engineering that would blow most "audiophile" pop releases out of the water. Put simply, where acoustic instruments matter so shall there also be first-rate recording work.
Now, this isn't a universal maxim, even among so-called "demonstration quality" records. Let's remember Zubin Mehta's LAPO Planets on Decca, which is spot-miked to the point of perversity, though some folks like to use it to show off their equipment. That's a noble-enough cause, especially in modern society, but let's not pretend it sounds natural or even particularly good. Of course, there are some records that get the treatment that deserve it, like Lovro von Matačić's 1967 Bruckner 7th with the Czech Philharmonic, which received the JVC XRCD24 treatment - though the set is Japanese and usually available only through specialty shops (though it's still cheaper here than in Europe). In other words, the baseline sound for 'classical' releases is very good, but "audiophile" recordings are more of a mixed bag.
Except in two cases: RCA's excellent Living Stereo reissue series and what of Decca's Mercury Living Presence project remains. Since UMG has been so slipshod with the Living Presence reissues (and since the redbook layers are identical), I'm just going to talk about the regular CD reissue series from the 1990s. They were supervised by Wilma Cozart Fine, who played a not-insubstantial role in the initial releases. The discs, which of them you can find is largely up to you - I've had good luck at various Barnes and Noble stores, are relatively cheap, mastered intelligently, and better than good. Now, whether or not you really have to have Frederick Fennell and the Eastman Wind Ensemble playing a transcription of the finale from Rheingold is up to you, but there are some gems among the discs (Starker's Bach cello suites are well-regarded, and I'm a big fan of Byron Janis' Pictures at an Exhibition). The sound is as good as one could want.
Another instance of this is the RCA Living Stereo SACD rerelease series. I don't know if they went back and polished up the redbook mastering from the 1990s CD series, but, even if they didn't, it sounds great. Clearly, the producers and engineers cared about sound and capturing great conductors like Fritz Reiner and Charles Munch with ensembles like the CSO and the BSO. Pick up Munch's 1959 Saint-Saens 3rd symphony, and wait for the four-hands piano in the Maestoso (e.g., rehearsal figure S on p. 126 of the Int. Music Co. score). It's nice. The RCA catalog is full of moments like that, which is to say music that's played competently and recorded wonderfully. Of course, having Fritz Reiner and Charles Munch around never hurt anything or anyone.
The main draw for the RCA SACDs is, of course, the three-track SACD layer, which reproduces the three-track masters used to get the "Living Stereo" sound. Whether that's your thing is, necessarily, your decision. Frankly, the vagaries of multichannel sound have eluded me to date, not least because most stereo recordings do a pretty good job of creating a soundstage, and the Living Stereo (and Living Presence) stereo mixdowns do a better job than most. Really, reference-quality, at least to me, means that the vector doesn't get in the way of the information it communicates - i.e., transparency. While, if you take time to listen critically, the sound is pretty darned good, the Living Stereo and Living Presence sets have sound that doesn't get in the way.
To put it another way, they, as a consequence of not using thirty tracks, sound pretty natural.
They're also relatively cheap. Oh, glorious amortization, especially when it took place long before I was born.
Putting it all back together, the RCA Living Stereo sets - in particular - sound better than pretty much every pop release out there and a good number of 'classical' discs, they've got great conductors and ensembles, and they're priced to sell. If you're serious about audiophile-quality sound, you might as well start here (assuming you're into serious music), since these provide a good introduction (albeit a half-century old) to the idea.
Enough of my gassing, though.