Um, Jack Johnson is great, but he's certainly not classical.
I think he's referring to classical music (eg Sor, Granados, Bach, etc).
I'd say Fabio Zanon is perhaps the most impressive classical guitarist I've ever heard. You can't go wrong with the recordings of Julian Bream, Andre Segovia or John Williams, either [with one caveat- most of Segovia's recordings are mid-fi at best; he died years ago and some of his material is mono- the performances are great, though].