The sound of a good band going full tilt, using tube amps, drums and vocal cords utilized within an inch of their life.
Top Fuel Dragsters. Nothing your living room will produce gives the sound justice, unless you can feel your home stereo system in your chest. That video almost does the experience justice.
And yeah, the airport has amazing sounds.
That hush in the air after a big snowstorm.
Similarly, that almost anti-sound when it’s 20 below and too cold to snow. The sharp crystal feeling almost has a sound but not really.
A nice memory from my childhood: My mother saying, “Go on back to sleep; you don’t have to get up for a while.” For a small child, it was a wonderful sound.
Another one extinct for at least fifty years: The sound of a fare box on a bus or trolley sorting out the coins dropped in it: chunketta-chunketta chunk. (You see, exact change was not required on public transportation until the sixties, and as the bus or trolley moved along, the fare box made this soft murmuring sound. Chunketta, chunketta, etc.)
The ding-ding-ding of a bell warning of an approaching train at a grade crossing. as the crossing gate came down.
Amen to whoever mentioned the thunder of a supercharged fuel dragster.
Playing cards being shuffled.
The clunkety-thump of an old-fashioned soda pop dispenser dropping a cold bottle of pop down to the person who put a quarter in the machine.
The cry of a loon when there is no one around.
A woodpecker doing its job.
The first chord in A Hard Days Night.
The opening guitar riff in When Doves Cry.
“And our snow cancellations for today…Saint Mary’s…” YAY!!!
The sound of a freshly opened glass bottle of coke.
The sound of an audience applauding you just as your show ends.
The sound of your SO screaming in pleasure during an orgasm.
The little grumbly noises Leet the Wonder Dog[sup]TM[/sup] makes when he is getting his nightly brushing and combing.
And the chunkachunkachunkaWHOOOOOSSSHHH when the Roto-Rooter guy got my main drain unblocked.
Regards,
Shodan
The generator kicking in after the lights go out.
Pipe organ
This gets my vote.
Today started with my 24 month-old climbing into my bed, lying on his back, and using his legs to push me out of the bed, all while belly laughing like it was the funniest thing ever. Best start to a day I could conceive. 
The distinctive squeaking sound you get walking on a thin later of snow on a very cold day.(Yeah, I’m from Southern California, and to me this is an exotic sound.)