Use a font size between 10 - 12 and a sans - serif font like calibri or ariel. (careersidekick.com)
Also, even if the line spacing is narrow, like 1 - line spacing with no gap between them, calibri letters tend to make their own space and distributes well, making it pleasing to the eye of the beholder. (avidcareerist.com)
Use professional font such as times new roman, arial, tahoma or calibri. (topsampleresume.com)