Arial, Helvetica, and Helvetica Neue must be stopped. Here's how, even if you don't have a suitable replacement installed. In this style, I use Open Sans.

There are some other fonts, like Arial Black, Times, and Times New Roman which also deserve to be destroyed, so again let's replace them with much better Google Fonts.

A couple areas are commented out, to be available as an option should you rather use a different replacement. More options are forthcoming.