What is your favorite Addon?

I love Advanced Sprays, since it lets you spray GIFs and videos, and you can also restrict them to certain ranks if you want. So good: https://www.gmodstore.com/market/view/4234

I also have a love/hate relationship with Pointshop 2 though. It's a pain in the ass, and there's virtually no support from the owner anymore anymore but when it works well, it works REALLY well.