deadmau5 - Strobe
One of the more polarizing musicians out there (only a few notches above Skrillex in terms of popular opinion), I'm actually a pretty big fan. This is universally recognized as his best track. Long wind up, and it's very gentle and calming. Perfect to put on in the background or for a late night walk. I've got plenty more deadmau5 recommendations if you like him.
Giraffage - SLO
I've got heaps of really calm/chillout/ambient stuff like this, but I'm mostly leaving it off this list. Lemme know if you want to hear more like this.
Spor - Pacifica (Kito and Reija Remix)