Luna

I would add:

cheat - a tool that lets you make and use your own cheatsheets

gomi - replacement for the rm command that has a trashcan, so if you accidentally delete something important you can just restore it

bat - modern cat, with features like syntax highlighting, line numbers, etc

eza - modern ls, with cool features like file icons

broot - a different than ranger/lf approach to navigating folders

mdr - a markdown viewer

Also, I think you should add a note that ranger should be installed from git because most distros package version 1.9.3 and that is 4 year out of date and has lots of bugs that have been fixed in the git master branch