I tried a few charting libraries including Chart.js, Taucharts and D3.

Much of Taucharts is undocumented, Chart.js requires a lot of configuration for something like a mixed chart with stacked bars, and D3, yikes. Its API documentation is thicker than Ulysses.

Highcharts required minimal configuration, had an intuitive and clear API and - most importantly - handled all sorts of messy data I threw at it. It just worked, out-of-the-box.