Any of Leo Kottke's stuff esp from the early 70's to 1986 when he got hand troubles. '6 and 12 string guitar' is probably his most popular. problem is , LK's stuff is not easy to learn but TABs are available on the net.
'Only'by Tommy Emmanuel is a masterclass in finger picking style.
Martin Taylor's 'Artistry', 'Portraits' and 'Solo' albums are definitive guitar only jazzers.
Adrian Legg's probably the greatest player of electro-acoustic guitar although his best CD is his most recent 'Guitar bones' played on regular acoustic.
Martin Simpson's made some excellent folk-blues-celtic stuff. all albums recommended.
Michael Hedges is probably the last word in taking the acoustic guitar to its limits. 'Aerial boundaries' is pretty much a classic among acoustic fans.
Acoustic shredding at its best - 3 CDs by Al di Meola, Pace de Lucia and John Mclaughlin. best is 'One night in San francisco'.
For flat picking you've got gypsy jazzers who are Django influenced like Bireli Lagrene and Fapy Lafertin who are excellent. Dan Crary probably plays some of the fastest and cleanest lines you'll ever hear. just listen to 'Guitar' and 'Bluegrass guitar' . Same goes for Tony Rice. On 'Devlin' and 'Backwaters' he fuses bluegrass and jazz.