There are many awesome sounds in this world...but there is one that never fails to give me the chills and the goosebumps.
The sound of a P-51 Mustang going by.
Of course, a Ford Mustang with the right exhaust system fitted sounds great too. And the sound of a good explosion is pretty great.
Automatic Weapons from a distance sound cool. A-10's flying over, radial engine warbirds....
On to more calming things...
Dead silence can be calming. And most definitely the rain. Bugs in the woods at night.
Just can't think of any more.
Of course, music is good.