texlive now has about 150,000 files, and thousands of packages. I obviously don't know the vast majority. I only know what I regularly use. A long time ago, the LaTeX Companion was my bible, but the most recent edition was so long and is so old by now that I had to give up on this one, too.
is there a list of "most important" and "most popular" packages that I should be aware of but am not yet aware of? unfortunately, there is no "public use" counter for latex packages :-( .
I did a quick scan through my hundreds of latex files over the years to identify my own list of most used packages, which contain
- amsmath
- array
- babel
- booktabs
- caption
- color
- float
- graphicx
- hyperref
- microtype
- needspace
- rotating
- setspace
- ulem
- url
- xcolor
I would consider latex almost useless without about half of these packages. I also use beamer and tikz, too---not as often, but important. (I am still keeping an eye on lualatex and context; and every two decades, I am checking back on latex3.)
I think novices and experts would both benefit from a list of "need-to-know" great packages for latex users. what other essential common packages that every latex user should know did I not list?