Many books have mattered enormously to my life and work. 'David Copperfield' by Charles Dickens would be one of several contenders for 'most influential.' I first read it at 13 and have reread it dozens of times since.
I myself love getting cookbooks and novels that some congenial person has already tried and liked.
I listen to lots of music, especially Bach, opera (all periods), German lieder, chamber music, and rock, old and new. I can't listen to music while I write. It's too absorbing.
I published only in academic journals in philosophy until I was in my 40s, but I had been writing fiction and poetry my whole adult life - without ever once trying to publish it, and rarely letting anyone read it.