We all have seen the 'Most Annoying Noise' thread, but what sounds do you consider pleasant?
In no specific order,
The laughter of my cousins (the only childrens'* laughter I can stand)
The Mario theme song
The satisfying crunch you hear when you shoot the head off a Super Mutant in Fallout
I'll add others later.
*I'm not sure if it should be childrens, children's, or childrens'. Damn english.