These are my top 5 favorites. Use them to make working with #terminal easier and efficient. - YMMV
First and foremost, if you are on Mac replace your terminal with iTerm, a much more powerful powerful terminal emulator.
Fishshell: I love the autosuggestions. Saves way too much time. There are many other useful features as well.
thefuck: Misspelled a command? Use this simple command to correct typos. There is no need to retype it.
HomeBrew: Easy installation of apps. On Mac, the cask install feature comes in handy and removes the need to drag applications.
cd. This is a much faster way to navigate your filesystem. It maintains a database of the directories you use the most from the command line.
TLDR: Concise man pages with lots of examples, just the way we want.