There isn’t a go-to programming language that is considered the best to use, so I’m not going to simply tell you one name, there’s no such secret recipe for developing security tools. It is much wiser instead to make a comparison between the most used programming languages and be ready to some flexibility. Technologies change and so we need to adapt; besides as you learn new things, you have a wider choice than you had before. Don’t be static, allow some dynamism, be willing to learn and improve your skills each and every time you get a chance to do it.