I'm don't know much about non technical things but I'd find a good understanding of electricity, electronics, automation, manufacturing and robots are very interesting although not directly related to hacking or CS.
Math is always good to know. (especially if you hope to know more about machine learning, those books tend to be math heavy)
And knowing something about basic psychology(mainly how people are sheep) might help in some social engineering situations. Pretty much anything that improves your social skills would be useful for SE(and life).
Design is important if you want your application to be pretty(standard CS classes don't really focus on this beyond basic photoshop skills)
Logistics, accounting or economics might be interesting if you hope to find a CS related job in those sectors. But I find them boring.
I guess all these terms are pretty wide and vague and maybe not very helpful, I wonder what other people have to say about this.
<Yoda> if someone says something i don't like, i ban him, ban whoever defends him, and then ban the witnesses...