OS on my PC is Windows 10 for some specific things I need it to. I'm sad I can't use Linux on my main machine for now. On my laptop I use Arch Linux - It's the best distro I ever used. It's great because It doesn't hide how your system works and It's fully customizable. I use the lightweight basic Xfce GE, It's also the best GE choice in my opinion because It's stable and still looks unique and great.
Firefox and ungoogled chromium - the only good web browsers I used
Foobar2000 - not open-source and made for Windows. It's obviusly not the best music player
but I'm very used to this design and It's made by trustworthy guy.
MPV and MPC Windows 10 fork - Video players
Telegram - not open-source, has optional End2End. Still trustworthy for me, staff refuses to work with feds. Matrix - open source, basic End2End, strongly designed for security. IRC - old but still very good, not designed for security.
Visual Studio Code - only good for web development PyCharm - Python specific IDE, kinda comfy I use only 2 IDE, the whole rest I do in Vim.