My personal favourite is Steve Hackett. He's done several: Bay of Kings, Momentum, and the occasional track here and there, but the best (my personal favourite, anyway), is A Midsummer Night's Dream. I think Sketches of Satie is all solo acoustic guitar, too.
Classical guitarists: I believe the two biggest guys in the field are Julian Bream and Andres Segovia, the latter of which is considered to be the "Heifitz" (?sp) of guitar. One of the most important pieces in the genre is Rodrigo, "Concierto de Aranjuez". No, I cannot recommend one particular version (not familiar enough), but if I had to buy "blind", I would go for either of the above two.
John Williams also appears a lot (search on allclassical.com). No, it's not that John Williams...
EDIT: Ignore the "Concierto de Aranjez" rec, it's got a whole orchestra behind the classical guitar. But the artist recommendations stand -- Segovia, et al.