As detailed in Rolling Stone cover story, the Grateful Dead are preparing to officially call it quits after 50 years with their series of Fare Thee Well shows. Their absence will end a legacy that continues to span rock, pop, folk, jam and avant-garde music. We asked a diverse spectrum of artists — from their rock heirs in My Morning Jacket and Black Crowes, to pop champions in Bleachers, to the adventurous alterna-types in Sonic Youth and Animal Collective — to pick their favorite song.