We have settled on nodejs and or Node.ACS when building these applications and have dabbled with different frameworks for the front-end of the tools. Over the last few weeks I have been reading about AngularJS and watching alot of videos on the framework and I must say I am impressed.
From the website
HTML is great for declaring static documents, but it falters when we try to use it for declaring dynamic views in web-applications. AngularJS lets you extend HTML vocabulary for your application. The resulting environment is extraordinarily expressive, readable, and quick to develop.
Another great integration with AngularJS is integrated unit testing with Karma ( use to be called testacular ), see the video below for a quick introduction.