Can someone make recommendations for me? Here's what I already know and what I've built with it:

- Java. My first real programming language, learned in college, used for a year and a half in enterprise work and Android, got pretty good at it, but I learned

- Objective-C for making iOS apps and I never want to write in Java again. I'm also learning C just to understand Objective-C more but I have no plans building anything with C.

Basically, my current interests/goals for learning a new language are:

- Develop a new way of thinking.

- Learn some great engineering practices.

- Build products (software) that solve real-world problems. I'm not likely to learn a new language if I can't build anything useful with it, that can potentially sell and make it as a consumer startup.

- Become full-stack. I can already easily build an iOS app (I have no interest in building responsive websites) but I find myself still having to rely on something like Parse. Which isn't so bad though because it saves me so much time.

I guess that narrows my choices down to: Ruby, Python, Go, or something else, but I'm not in a position to identify which poison is best-suited to me. I just want one that I can be really good at and meet most if not all of my goals. Any thoughts?