Ruby's not used a whole lot, and Python is basically what Java should've been. Python is a beautiful, easy, and simplistic language, try it out. Java's the same but with a C++ syntax and some rather dumb arbitrary limits.
Well I was more wondering like which to start with. I leaned more towards Java, Python and Ruby but dunno which to pick...
Started learning C but never did finish.
When you have a program that has a specific job to do (say, a compiler or a file converter), the command line works fine. Even database management programs could be done within the CMD with a little work. However, if you're making a program that is used for consumer pleasure or entertainment purposes (such as a web browser or word processor), or requires visual editing to make sense (such as a map editor or web browser), a GUI is a must. And it's easily do-able in C with a small amount of work through Windows.h. :)