bradshaw of the future has a post called “The ten coolest languages”; obviously any such top-ten list is to some extent subjective and arbitrary, and this one tails off at the end (“Sanskrit has a cool compounding system,” “Telugu: Because it has such a beautiful script”), but the ones chosen for their phonetics are truly astonishing. Number one is Austronesian languages of Vanuatu: “The languages of Vanuatu, like Vao, Tangoa, and V’enen Taut (Big Nambas), are I think the only languages in the world to use linguo-labial consonants. These consonants are made by touching the tip of the tongue to the upper lip.” Number two is Salishan languages:
Here are some words in Klallam. (ƛ̕ is a lateral ejective /tɬʼ/, c is /ts/)
sk̕ʷc̕ŋíyɬč “cherry tree”
The orthography is an accurate representation of the pronunciation. There are no epenthetic vowels; the word for “Friday” really does begin with 6 consonants.
Mazatec “contrasts creaky and breathy voice vowels”; ǃXóõ “has five basic click consonants, each of which can be modified in various ways, for a total of over 80 click sounds.” And there are audio files for many of these amazing phenomena!