We use Vega-lite. We really like it. After using hodgepodge of different libraries we've settled on this one. (I've used D3, C3, highcharts and some others)

The documentation on features is kinda ok (vega lite sets a lot of defaults). but it works really well. Vega is more full featured but more difficult. The ability to be able to easily add download as SVG and PNG is fantastic.

You can open an example and play with the configuration online. (Click on an example and find the link to "edit online")

https://vega.github.io/vega-lite/examples/

Vega lite is built ontop of D3 I think.

They have a intro documents called "Data Visualization Curriculum" which can be helpful.

https://observablehq.com/collection/@uwdata/visualization-cu...

And the VS-plugin for Vega/Vega lite: https://github.com/RandomFractals/vscode-vega-viewer