Since i've begin to use Lua hacks on NO ANTICHEAT servers in 2014/2015 i have discovered many gmod hacks, private, free or leaked. They all had their pros and cons but from 2016 to 2018 i had the pleasure to meet BigPackets, a free user-friendly and almost fully customizable undetected c++ hack, with lots of features and heatlhbars i must say its the best hack you can find, it beats the crap out of paid lua cheats like Citizen Hack and you should totally test it
