The Windows setup for everyone (with free software only)

I prefer to use this instead of the default File Explorer because it has tabs !

Worth mentioning :
Explorer++ For nostaligics
Double Commander For nerds

A nice chromium browser with ads and trackers blocked out of the box !
Worth mentioning :
Mozilla Firefox (Check Arkenfox if you want more privacy , install uBlock Origin )
LibreWolf If you want Firefox engine with more privacy out of the box
Vivaldi (install uBlock Origin )

If like my you use multiple browsers daily this one will be useful. Set it as your browser by default and when clicking on a link it will prompt which browser you want to open.

I prefer this one over the default Microsoft Photos

Worth mentioning :
nomacs
qView minimal af
opti
IrfanView Customizable af

I prefer to use AIMP instead of Groove Music

Worth mentioning : Museeks

The king of media player, better than Films & TV

Worth mentioning :
MPV
mpv.net Simpler lighter version of mpv

I do prefer this Mark down text editor over Notepad !

Worth mentioning : Notepad++

If you read ePUB on your PC I would recommend you this one.
For manga lovers check : HakuNeko

Worth mentioning :
Thorium Reader AudioBooks also supported !
YACReader Comics focused
calibre

A free PDF reader if you need advanced features ! It will probably try to install McAffe or other stuff SAY NO!!!

Worth mentioning : PDFsam Basic features on free tier

If you game on PC you know
GOG GALAXY DRM-free games so you own them for real.
Epic Games Store They gives free games every week, and 88% goes to the game editor/dev
Origin If you suck
Ubisoft Connect some games require that shit
Battle.net App Why not
itch.io BE CAREFUL TO DOWNLOAD TRUSTED GAMES BECAUSE SOME UNKNOWN SHITS ARE VIRUSES!!!

If you want to emulate retro games this one is gold when you know how to use it !
Internet have tons of tutorials so you can master it !

If you want standalone emulators :

GBA : mGBA
NDS : melonDS
3DS : Citra
Gamecube and Wii : Dolphin Emulator
WiiU : Cemu
Switch : Yuzu

PSP : PPSSPP
PSVita : Vita3K
PlayStation : DuckStation
PS2 : PCSX2
PS3 : RPCS3
PS4 : GPCS4 EXPERIMENTAL don't expect much of it for now !

Xbox (OG) : Cxbx-Reloaded
Xbox 360 : Xenia

Master System : Mame
Saturn : Mednafen (MAME can also emulate saturn)
DreamCast : Redream

For more check : https://alternativeto.net/list/29770/the-ultimate-emulator-list/

On PC you have too many choices for game launchers. Put all your 3rd-parties libraries (Steam, gog, Ubisoft Connect, etc...) in one single beautiful place !

GOG GALAXY can do it too !

Windows 11 wil have some android app support but if you're on 10 this might be nice if you want android games on your PC !

Worth mentioning :
BlueStacks
LDPlayer
GameLoop

If your friends game on PC, they probably use this one to communicate !

If you use a dedicated GPU this tool is really nice even if you don't have an MSI graphic card. It shows video card stats (temp, GPU usage, etc...). Allows overclocking, controlling of fans, etc...

For NVidia GPU !
It let you customize your drivers and NVidia related software, so it allow you to uninstall things you don't need/want !
Worth mentioning : TinyNvidiaUpdateChecker

If you have RGB on your gaming RIG this helps you manage them for any constructor like Razer, AORUS, ASUS, MSI, etc...

To manage games backups !

Worth mentioning : Game Backup Monitor

A nice tool to manage your mods. If you like to tweak and experiment with your games this one is gold !

Worth mentioning : Vortex Peviously known as Nexus Mod Manager

To use Dualshock (PS4 controller) on PC

If I have to do some image manipulation or photo editing ! (it's a WebApp)

Worth mentioning : GIMP with PhotoGIMP

If you do photography this is useful for photo editing !

Worth mentioning : Polarr