The question could be changed to: “what’s your favorite programming language?”
I would said that this is a subjective question, as everyone has different opinions in expressiveness and design, and the productivity also depends in your experience.
On my case, this language would be Ruby, as that’s where I feel at home.
I largely agree with this statement. I think the original question is very widely scoped. It’s like asking, “what’s the best tool for hammering nails, chopping wood, cutting wood, cutting glass, polishing floors, and building skyscrapers, and the tool is used by all builders anywhere and any time in the human history?” Different people, different skills, different problems.