I would love some suggestions on great acoustic...

Michael Hedges and Nils Lofgren are excellent choices that offer great sound/performance quality. Another "audiophile" recording that wasn't mentioned is "Friday Night in San Francisco"-DeLucia/DiMeola and McLaughlin. On the mellow side Laurindo Almeida and Charlie Byrd mix classical with jazz. You can't go wrong with any of these recordings especially on the Concord label. Since you mentioned vocals Almeida with Sammy Davis Jr. is excellent in performance and sound quality. It has become a favorite "chill out" recording of mine.

I second Bruce Cockburns' Speechless, awesome performance and recording. Any Steve Howe solo albums, Craig Choquico,
(spelling may be wrong) is another that comes to mind.

Antonio Forcione's "Tears of Joy" and "Meet Me in London".

Manuel Barrueco--Albeniz/Granados, Vox LP also available in a 3 CD VOX set (I think it's called something like "400 years of Classical Guitar)

FOLK/COUNTRY/BLUEGRASS:

Doc Watson; Doc and Merle Watson
Ricky Scaggs
David Grissman(madoline)
Ry Cooder -- Paris-Texas soundtrack.

JAZZ:

+1 to John/Paco/Al
Bireli Lagrene
Egberto Gismonti mostly found on ECM label is new age/jazz solo guitarist.
Vlatko Stefanovsky/Miroslav Tadik acoustic albums -- EXTREAMLY ADDICTIVE! Once downloaded, I couldn't stop listening for weeks.
Filip Catherine(who once trained Larry Corryel)
Jim Hall/Pat Metneny acoustic duo

CLASSICAL:

Certainly John Williams!
+1 to Manuel Barrueco; -- They are veterans both
today's classical guitar maestros:
Rolan Dyens;
Jason Vieaux;
Ana Vidovic.

EXPERIMENTAL AND MODERN CLASSICAL:

Goran Ivanovic/Andreas Kapsalis acoustic duo. Goran also released his solo album as well.
California Guitar Trio also Robert Fripp String Quintet 3+2 with California Guitar Trio and Tony Levin(stick bass, fender bass).