Kitty purrs ~ I just love it when my kitties purr; it's my absolute favourite sound. And I love it when the kitties at the shelter I volunteer at purr; given that they are there with other cats, having been abandoned by their owners or found on the street, it melts my heart when they are content enough to purr for me.
I love the sounds Chester and Piper make when they're sleeping. Chester makes these little grunting sounds, or he sighs, and Piper makes this squeaky noise (hence one of her nicknames being "squeaky nose"
)when she's starting to go to sleep. Nala and Ariel are usually pretty quiet when they sleep.
My kitties meows ~ Ariel, when she's purring and meows at the same time; Chester and Piper when they're playing with their toys - they talk to them! It's so funny to hear them downstairs meowing at them. And Nala, she has this chirpy meow she does when she's greeting me.
And an odd one ~ the sound of a fighter jet flying overhead. That's why I love going to the airshow here. There's just something about the sound, I can't explain it.