For my operating system I use
When it comes to operating systems, you really can't go wrong with Linux.
I use Void Linux because it is highly customizable and uses very little system resources.
For Linux beginners, I recommend Linux Mint since it is very user friendly.
I truly think that Unix based/like systems are superior to any other operating system.
For my web browser I use Firefox. It's way better than Chrome, Opera, or Microsoft Edge for many reasons. First of all, Firefox is perhaps one of the most customizable browsers out there. Second, Firefox is perhaps one the oldest browsers browsers that is still being supported and updated. Lastly, Firefox is free software, which automatically makes it better than any other propritary web browser.
My window manager of choice is dwm (dynamic window manager). I was pretty hesitant when I first switched over to a window manager because it seemed pretty tough to use. However, I eventually got the hang of it and now I think that a window manager is way better for productivity. I use dwm in particular because it takes up very little system resources and it is very customizable. Although it takes some knowledge and skill to learn and customize dwm, it is well worth the trouble.
I use st (suckless/simple terminal) for my terminal. st is very small and uses barely any system resources, it is also pretty customizable and extensible. I goes along pretty well with dwm.
For my shell, I use zsh. It's compatible with bash and has a few features that I find very useful like syntax highlighting and auto completion.
For text and code editing, I use both Vim and Emacs. They are both very good editors, I mostly use Vim for quickly editing files and I use Emacs to work on larger files and projects. I have yet to decide which one I like more...
I use Libre Office. Don't pay for Microsoft Office!!! Libre Office can do everything you need for FREE! Although I use Libre Office for most document-like needs, I am thinking about using other programs. groff and LaTeX are both promising looking document compilers. sc-im is also a very nice looking spreadsheet editor with various features.
For video I use mpv, almost everyone is using it nowadays and it's very versatile. For audio I use mpd and ncmpcpp. mpd is the daemon that runs underneith ncmpcpp that sorts the music, plays the music, and etc. ncmpcpp is a very feature rich client for mpd that works very well.
For image viewing I use sxiv because it's very simple. For document viewing I use zathura with different add-ons for PDF and document viewing. And finally, for presentations, I use sent for its simplicity.
I use neomutt, which is a "better" version of mutt. I use a terminal based email client because when it comes to webmail, it can take forever to actually get to your email. First you have to open a browser, then go to your webmail site, then login. Neomutt does all of that for you.
This is misc. software I use that does not really fit into any category.