At the present time,just as you hit 4,500 revs on my Speed triple 955,that chesty roaring bellow from the airbox,intoxicating soundtrack...                                                                                                                                                                             

Oh,and that scriiiiiitccccchhh noise when i run a spoon handle round the foil on a new jar of coffee to relese it's contents...simple pleasures....bees buzzing,Nacho gargling like the Soup Dragon when he's waiting for his full food bowl...better stop me now,Catlkins,lol :)>

Sea waves hitting the shore and retreating back over the pebbles/rocks.
Blackbirds singing at 4am
Washing machines on the wash cycle (very hypnotic!)
Foxes barking at night.
Peacocks calling.
Rain
Just a few of my favourite sounds, not forgetting the nicest one of all at times.... Silence!

A Harris exhaust on an old air-cooled Kawasaki Z/GPZ, or on Suzuki's old air-cooled GS1000 and GSX1100.

And the Vance & Hines Supersport pipe on oil-cooled Suzuki's GSXR1100.

Far better than ANY album I own, have ever owned, or ever will own!! :-)

ps: A 3 into 1 exhaust on a Triumph T150 sounds lush too. So does a set of decent pipes on the Z1300, and the CBX1000. Then there's the whole 'Swarbricks on an LC' 2 stroke thing as well.

pps: Looks like my favourite sounds revolve around bikes. Only. I tried thinking of other things but all these amazing sounding bikes kept popping into my head. Just like Mike Hailwood's 6 cylinder Honda 250 has just done.

ppps: There's just too damned many!!

Know where you're coming from, a Moto Guzzi 500 V8 being accelerated hard out of a corner makes the hairs stand up,too.....                                                                                                                                                                             

Almost forgot about engine noises, how could I lol? Admittedly though I am more of an 'American Muscle' car engine noise lover than a bike engine one (shock horror!) x                                                                                                                                                                             

The Dawn Chorus in summer.
                                                                                                                                                                             

Some years ago, Bike magazine released a CD called World Of Noise.
There are 18 recordings of bikes in various scenarios, including Norton rotary, Fireblade, machines on the Barbon hill climb, Speed Triple,  ZX-12R speed run, Goodwood festival of speed...
It finishes with a Ghezzo Brian Supertwin being ridden into the garage after a long run....engine switched off...ticking and pinging as the engine cools.

Quite hypnotic for armchair listening.

On a more sane level, I do enjoy the sound of a local church bell practice floating into the garden on a summer breeze at dusk.

@ Eliza Dee
The growl of a Chevy V8 is very hard to ignore - the Shelby GT350 is just...sigh

Would have to agree with Elizadee on waves and beaches,especially if they've a band of shingle....calming..:)>                                                                                                                                                                             

Snoring/Dreaming dogs...velcro being peeled apart,depending on the situation...:)                                                                                                                                                                              

Straight through 3 into 1 pipe on my old Triumph Trident 😊                                                                                                                                                                             

Laverda Jota with the 120 degree crank. :-)