Both Angular and Ember. I love them both. Sue me.
I've written 2-3 large applications in Angular, I've contributed ~1200 lines to Angular 1.3, and racked up a lot of points on StackOverflow answering questions around Angular.
However, I'm currently working on a pretty crazy real-time app for Netflix that's all in Ember, and I wouldn't have it any other way. I have the pleasure of working with @ebryn there, and it's been an awesome experience.
In this poll, there are really just those two frameworks. The others frankly aren't in the same league right now.
I've yet to read what I thought was an unbiased, honest comparison of the two. Generally, anyone that does a comparison has one favorite, and the other they barely know. I'm hoping to remedy that at some point, but I still feel my Angular experience out-weighs my Ember experience. At least for now.
However, preliminarily, I can say that both frameworks are absolutely brilliant attempts to solve similar problems in completely different ways. I think they both have a LOT they could learn from one another. I prefer a convention-based approach, which is one thing I love about Ember... That said, I prefer Angular's constructor-based DI over the setter-based DI of Ember... That said, both of them have somewhat primitive IOC containers that could be better (which is a whole blog post by itself)... THAT said, Angular allows developers to put too much logic in their templates via expressions (harder to test)... THAT said, Ember's structure and composition isn't quite as easy to pick up if you're new to the framework... THAT said, Angular doesn't require any other libraries and is very compact... THAT said Angular's directives allow for wild-west spaghetti code and give developers enough rope to hang themselves... blah blah blah
... the point is, I could go on forever. Both libraries have REAL advantages over one another, but libraries have REAL disadvantages over one another as well.
# Embular.js in 2016!! Change the world!
What I'm hoping for is that the incredibly brilliant minds behind these two efforts see the light and join forces. Even work with the folks designing ES6/7 and the future of HTML/DOM...
What I'm hoping stops is the "my framework is better than your framework because _______." silliness.