The short answer: When in doubt, set your text in a font that’s easy to read. And then they are so many extra ways of adjusting them (uppercase, size, color, …).
Many of these typefaces come in different fonts (thin, bold, …). How should the text appear in your data visualizations? The possibilities are endless: There are millions of typefaces out there (Arial, Times New Roman, Lato, …) belonging to different categories (serif, sans-serif, condensed, wide, …).
