I wrote about this back in 2013 and things have changed since then.
My current daily drivers and important tools are..
Wireshark – still use this constantly and almost daily
CyberChef – An easy to access tool for data conversion, encryption and decryption.
PowerToys FancyZones – Incredible desktop snapping and organisation tool.
Alt-Tab Terminator – I now have so many screens open at once; this tool allows me to search the alt+tab list.
(The last two functions are built into the Pop!_OS linux distribution which I intend to try one day as Windows slowly gets more bloat and less customisable.)
nmap – Network scanning and service discovery.
PuTTY – SSH client.
TightVNC – Simple and versatile method to remote to computers.