Funny you should ask this because yesterday I sat and watched a Squirrel in a tree whilst it was making a right racket .
It kinda sounded like a wounded bird sound but it was really going for it .
Wether it was a mating call or a warning call to other squirrels saying " theres an annoying human watching me " I dunno.
But to answer your question my favourite animal noise has to be the sound of my dog sleeping x