Which JS framework should I learn FIRST?

Let's face it. JS developers have a great problem - there's more interesting frameworks being intro'd each week. Being competent on multiple frameworks is hard enough if your main job is as a developer. As a product manager, I'm in a bind.

Why is a PM asking? Well, my company is pretty small & doesn't get application development at all. (Don't get me started. It's depressing.) So I develop an occasional app so that my salespeople can access information & manipulate it on-the-fly, instead of depending on MS Office crapware. I've graduated from simple static HTML to Ruby on Rails to (hopefully) JS-based tools.

I want to build these myself. I have the bandwidth to do them, I don't want to wait on my HQ staff to deliberate, and I want to add these skills to my background

So - which JS framework should I learn FIRST?

- Node - Backbone - Meteor - Angular - Ember - Other

OK, pile on. I'm completely open to ideas.