I am going through the hoops of learning Ruby right now. I have had previous, minor experience with Rails but I would highly recommend learning Ruby beforehand as Rails is just a framework for Ruby.
I was once at crossroads as i wanted to choose either c++, java or ruby. To say no more c++ won the day after a long protracted battle in my head. Ruby came a close second. I think i might just cheat on C++ and give ruby some time