Decision trees for Rstudio v3.3
The "best" package depends on your goals and data really.

A few tree / forest packages that I've come across:


randomForest - an implementation of the original algorithm
ranger - a flexible implementation designed to run on high-dimensional data (my personal favourite forest package)
party's ctree / cforest functions - conditional inference trees / forests
rpart


Some of these packages focus on forests rather than trees; you can coerce the forest algorithm into building a tree by flexing appropriate parameters.