This will be a growing list of the tools that have made my life easier and hopefully wil do the same for you.

I will try and limit this list to the best of the best. Everything else check out My Github Stars List there is loads on there

Windows

Mobaxterm - This is great for managing logo sessions to boxes when you are on a job. This has a nice SSH Tunnel tool. Also can spin up a number of services quickly web, ftp, smb…est
Ueli - This is a great app. have your own customizable launcher with some great plugins. helps speed up my workflow because you can access things so quickly I like the shortcuts feature alot
dngrep - powerful windows grep tool
AutoHotKey - Dont work harder work smarter. This can help you with creating macros and little scripts for things you do more than once or to speed things up..Automate it all!! I have released a few tools using this:
Vulnsearch - this will search on popular exploit websites for vulns for you
Secpol - Exports the GUI version from secpol.msc to csv file
NETworkManager a .net GUI network manager for windows - has a few nice features
SauronEye - This is a great .NET for searching for passwords in files
PowerToys - useful for custom snap window management and layouts
WinPEAS - great privesc script

Linux

ZSH - my new found love. sorry bash!! loads of plugins and customizability. Ive got a post on this
peco
duplicut - useful for making wordlists removing duplicates but keeping the order
fzf - fuzzy search
bat- like cat but better
Traitor - a cool priv esc tool to check the low hanging fruit
LinPEAS - privesc script

pwnfox - this is really good for seperation testing allowing you to have sandbox tab so can login with another account.
wappalyser - find out what technologies are used by the app
retire.js - This is good for findings vulnerable web components - jquery..est. The browser plugin is great - Firefox Addon, Chorme Extention
foxyproxy - quick and easy proxy switcher
start.me I use this like a bookmark dashboard and find it useful to quickly find resourece and get where I want to go. Checkout the dashboard I made https://github.com/shifty0g/start-me
Hack-Tools - A swiss army knife

Burp Suite - Pretty much the gold standard when it comes to webapp testing. it does so so much. It likes to eat all your ram . nom nom nom . The community version is great
Nuclei - This is amazing!. A community supported template based -vulnerbility scanner.
Nuceli-Template - Good to update them regullary
Aquatone - so far the best for web screenshots. can supply it a url list or nmap file
Httpx - another gem from the projectdiscovey guys. this will check if the url is alive. really nice output options
Concurl - run curl currently ;) then grep what comes out
FeroxBuster - This it the next evolution of gobuster and quicklybecomming my goto.
SQLInjectionWiki - Great resource to lean on when picking at SQLI

Burpsuite Apps - This is a useful online tool for finding burp plugins
Authorize - good for seperation and access control testing. works well with pwnfox. hoover in a low priv cookie and it will follow along ur browser high priv account

SecuirtyHeaders.com - Make sure to select private
CyberChef - Always one to keep bookmarked. Its is my go to when seeing some nonsense hash
endoflife - useful to lookup software to see if its EOL

nessus-file-parser - if you dont know about this one then now u do! This was a game changer when i found it . This amazing python script will parse multiple .nessus files to a spreadsheet that makes sense. This then gives you the power to filter and search in excel away from the horrid nessus GUI
ultimate-nmap-parser - I know shameless plug. I made this a long time ago and still use it most tests. This will parse out .gnmap files
nmap-parse-output - Another good nmap parsing tool
xurls - This will parse out urls from anything you pipe into it
gf - Another great tool from tomnomnom. essentially have a quick access grep library to run say over your concurl output

nmap - Lets be honest there is no better scanner. Never has never will. I dont need to say much else
RustScan - Super duper fast portscanner written in Rust
Brutespray - This is great for automated brutefocing. will take in a nmap file and blast ur wordlists. u may want to skip ssh and other tempremental protocls
nndefaccts - nmap script with better dataset for checking default creds
CrackMapExec - Another must for the toolbox. a swissarmy knife for smb and other ports. This is the big daddy
Scrying - take screeenshots of web,rdp,vnc - takes in nmap or nessus file
Pwncat - a nice little manger for your shells
Godance - useful tool to bruteforce SMB. compiled exe runs on old windows versions
PowerHuntShares - Really useful powershell script for checking smb shares
WinShareEnum - Another useful GUI tool for enumerting shares
Name-That-Hash - useful for figuring out what hash
ssh-audit - great to check ssh ports

Rengine - really cool automated recon tool. do alot of the basic checks whilst your feet are up

Statistically Likely Usernames
namesmash - helps building username wordlists
Mentalist - Custom wordlist generation
wordlist-tools - Shameless plug. this allows quick download of lots of good wordlist repos
PyDog - useful for making quick wordlist based on a single word
CeWL - scrape a website generating a wordlist

Mega.nz - I use this to sync my testing tools and notes. No client data ;) helpful if you have multiple systems and a nice backup too… FREE aswell
Ngrok - This is great tool for getting a public ip or address. I use this if i need to quickly run a web server over the internet
updog - host a web server for upload/download files.. really useful and can combine with ngrok