There's still time to help get the Durandal Kickstarter funded!
I love Durandal and I think it's the best MVC/MVVM framework for the web out there. If you already know how to use jQuery, Knockout.js and RequireJS then you'll have few problems getting up to speed quickly. It's the only framework I've found that works in the way my brain thinks about UI composition in applications. It's not as popular as the big frameworks such as Ember.js, Backbone.js or AngularJS but it should be.
Have a look at the video in one of the Kickstarter updates to see how it can be used to build single-page applications.
There are five days left to get this funded.