I turn to this game, A Murder of Scarecrows .
I've been playing this for years, There is something about the simplicity and eerie quiet of this game that really puts me at ease. In fact I can just listen to the sound of the crows and the swinging scarecrows and be relaxed.
I also love the artwork as well.
The sparse look of the graphics are inspiring and actually make me feel a little cooler.
Try it out.