Without judging any of the musical content, I find a number of SD recordings really shy of the audiophile mark.
KL -- It's decent sounding but there is a fuzzy quality to the highs and the vocals are too recessed. It is better on this mix but still below other SD recordings.
Nightfly -- really painful to listen to; digital, bright, harsh, strident. Almost no combination of gear (tubes, etc.) have made it sound very good or easy to listen to.
Gaucho -- bad in the Nightfly way. Moments of real audiophile bliss on here, but overall, it's hard to listen to all the way through. Glare-nightmare.
Aja -- very good to excellent but still not the best of SD or Fagen corpus.
Kamakiriad and Sunken Condos (Fagen) -- ok, now we're talking. This is a fantastic sounding album; lots of space, great midrange and highs. Lots of space.
Morph the Cat (Fagen) -- Also very good. This album is really crammed with overlays and so while it sounds sonically good (tonally), it's not the "wide open road" feeling I get from Kamakiriad and Sunken Condos.
Royal Scam is just ok; I'd put it between KL and Aja.
Y'all can fill in the rest. Or not.