Best guns for Gmod

I would say for traditional weaponry with no bases or added nonsense, The Murderthon 9000 weapons (otherwise known as M9K) are a good sized selection, ranging from small pistols all the way to a nuclear explosive. Otherwise, weapons made by Babel Industries are very well scripted and are (for the most part) quite unique from the rest, although it requires another addon (TFA Base) to be installed in order for them to work.