Don't do this:
first THINK what you need and then DOWNLOAD
instead of DOWNLOAD all and THINK later.
You wil be amazed how many packages there are on CRAN and GitHub.
On CRAN you can find TaskViews describing packages for certain tasks. Look there when you are not sure which packages you could use.
Of course you can always create a vector with the names of packages you are interested in and loop over this vector to do an install