Where do I go from Joe Pass?

Grant Green, Wes Montgomery, Kenny Burrell are definitely great guitarists to also explore. Green has a LOT of great Blue Note records and material available, which ranges from straight ahead jazz to more funky/soul stuff, latin, gospel and pop "ish".

Jim Hall is another great, his record with Sonny Rollins "The Bridge" is a legendary album.

Pat Martino is another guitarist I like a lot. Several great records like El Hombre, East, Live At Yoshi's.

Barney Kessel did a lot of work not always under his own name and was also a member of the legendary "Wrecking Crew" group of studio musicians.

Make sure you dive into all three of the Virtuoso lps that Pass recorded. There's no one equal to him, but you might want to give Baden Powell a listen. Powell also has a large discography, and recorded solo and group lps. He's more in a bossa nova vein; likewise, also try Charlie Byrd.
For pure guitar mastery, also try Yamandu Costa. Costa is thankfully still alive, and touring/recording and is unbelievably skilled - Brazilian and all of his work is acoustic.