I have this memory from when I was a kid. I was standing in the middle of the woods at my grandparents, watching big fluffy snow flakes fall around me. The only sound I could hear was a light breeze blowing through the pine trees. I don't know why but it almost felt magical. To this day I still love that sound.
I like to be able to hear whatever is going on outside. Ideally, that would also be silence, but if something is going on outside, I like to be alert and aware of it.
I'll also take a little rain and occasional thunder outside, as usually people aren't acting a fool outside during rainy weather.
thats hard but my top three is a light rain storm so just a bit of far away thunder, waves, and campfire. I have found some recordings of a compfire on a beach in a rainstorm and its just the best.
It's a tie between the sound of heavy rain at night and that strange silentness you hear when it's snowing heavily, the kind that you "hear" even inside the house which makes you want to go and check if it's snowing!
Rain and thunder outside while inside in the evening.
Also, due to occupational damage, the sound of an offshore seismic source going off in the distance ever 10-12 seconds. The sound and the low frequency shake of the ship means everything is working as it should.