OS X circa 10.6 – 10.9. Aesthetically pleasing, with lots of tonal contrast and touches of color to highlight important items. Clickable elements are clearly cl

OS X circa 10.6 – 10.9. Aesthetically pleasing, with lots of tonal contrast and touches of color to highlight important items. Clickable elements are clearly clickable, and the UI is reasonably dense, but it never looks overcomplicated or busy.