I'm sure we all want to say "everything." But restricting the answer asked by the OP, I'd say: Oboes/Bassoons.
I'm a soundtrack fan, and love Bernard Herrmann fan, especially the fantasy films - Sinbad, Jason and the Argonauts, etc - and his scores are notable for incredibly evocative use of the lower, growly registers of the wind instruments, especially Oboe, Bassoon etc.
One of the main aspects that attracted me to my Thiel (2.7) speakers is, aside from the authentic tone, was the incredible image focus and density to the sound. All this comes together especially right in the range of the lower registers of woodwinds. When a Herrmann woodwind is growling away menacingly, it's just "there" in front of me, a big, palpable instrument, vibrating the air in front of me. For a Herrmann fan it's just heaven. (I played the vinyl LP of Herrmann's Taxi Driver soundtrack, which has some killer moments of menacing solo woodwinds, for my musician brother and he was just in shock afterwards. Even though he's been listening to my various systems throughout the years, he said he's never heard sound reproduction like it.)