I was in your shoes about 6 months ago (experienced non-web developer, looking to expand my skill-set) and went with Rails. I took the Michael Hartl tutorial (highly recommend it), viewed some Railscasts and haven't looked back. I'm hoping to do a Show HN with my first side project rather shortly (I realize 6 months is a long time, but with a family and a job, I'm happy if I get 5 hours a week to work on it).
If I had to do it again, I wouldn't change my choice of technology. You can debate forever which technology is "best", but one cannot debate that the support system for learning Rails is tremendous.
If I had to do it again, I wouldn't change my choice of technology. You can debate forever which technology is "best", but one cannot debate that the support system for learning Rails is tremendous.