Is Andy Griffith and Ron Howard the only ones alive left on that show?
Andy Griffith (d. 7/3/12)
Ron Howard
Jim Nabors (3rd - 4th seasons)
Elinor Donahue (1st season, 'Ellie Walker')
Jack Burns (6th season, 'Warren Ferguson')
Recurring players...Betty Lynn ('Thelma Lou')
Maggie Peterson ('Charlene Darling')
Doug Dillard ('The Darling Boys') (d. 5/16/12)
Rodney Dillard ('The Darling Boys')
Dean Webb ('The Darling Boys')
Bernard Fox ('Malcolm Merriwether')
Keith "Little Ricky Ricardo" Thibodeaux ('Johnny Paul Jason')
Sheldon Golomb ('Arnold Bailey')
Margaret Kerry ('Bess Muggins', 'Helen Scobey')
James Best ('Jim Lindsey')
Sylvia Lewis (misc. characters in a few episodes; Desilu Studios choreographer who worked behind-the-scenes on multiple eps)
Rance Howard (misc. characters)
Clint Howard ('Leon')
Recurring players & MAYBERRY RFD regulars...Ken Berry ('Sam Jones')
Arlene Golonka ('Millie Swanson')
Buddy Foster ('Mike Jones')
GOMER PYLE USMC regulars...Ronnie Schell ('Duke Slater')
Forrest Compton ('Col. Gray')
Elizabeth MacRae ('Lou Ann Poovie')
And, lots of notable guest stars are still with us.