DataCamp have published an article on the five R packages with the most (direct) downloads. This is based on their leaderboard.
Packages 3-5 are currently swapping positions. As I write this (18 November 2016) the top five are
- dplyr
- devtools
- ggplot2
- cluster
- foreign
It’s notable that the list of the most popular packages is heavily weighted towards the manipulation and display of data. This is the bulk of the work done by data scientists.
The highest ranking analytical package is for performing cluster analysis. No surprise, really, as looking for groups in data is a very common requirement.