Rectangle
Provides window-snapping functionality similar to Windows 10
https://rectangleapp.com/

AltTab
Enhances Cmd-Tab functionality to show multiple windows from the same app, and a suite of other customizability options
https://alt-tab-macos.netlify.app/

Itsycal
Adds a quick popup calendar in the menu bar
https://www.mowglii.com/itsycal/

LinearMouse
Customize options for USB mouse.  Could replace DiscreteScroll and Sensible Side Buttons
https://linearmouse.org/

IINA
Movie and music player that plays pretty much everything.  Similar to VLC, but better performance and styling
https://github.com/iina/iina

Balena Etcher
An image/iso writer to usb sticks and sd cards.
https://www.balena.io/etcher/

Cyberduck
SFTP client, similar to FileZilla or WinSCP
https://cyberduck.io/

Keka
Archiving utility, similar to 7zip
https://www.keka.io/en/

OpenEmu
Gaming emulation suite for all retro emulation needs
https://openemu.org/

DosBox-X
Dos x86 emulator, allowing you to run DOS, Windows 3.11 and Windows 95 apps (even on an arm M1)
https://dosbox-x.com/

Right Zoom
Replaces the “full screen” green button with maximize
https://www.blazingtools.com/right_zoom_mac.html