What JS-framework to use in cooperation with MVC (6)?

So I've started, restarted, re-restarted, nuked, rebooted, started over, and restarted again a project the last couple of weeks. It's a new LoB application to replace an old aging ASP 3.0 application that is slowly dying a painful death, complete with COM+ objects failing and IE6-specialized code barfing all over the place.

I started with an Aurelia front-end and a Web Api 2 back end. Then the iterations went between different Web Api solutions until I'm now back on ASP.NET Core 1.0 on the full 4.6.1 framework using MVC 6. I know MVC, I don't know Aurelia - and the new constructs it brings with it - enough to be as productive as I need in the time frame allotted for this project.

But I still want some dynamicicity.. dynamicness.. dynamisism. (?) .. I still want the application to be dynamic and nice to use. With modals and other such niceties. Therefore my question is as follows: What JS-framework, if any, would you go with to add "bells and whistles" to a MVC 6 application?

And as a side-note, is there any way to get rid of/minimize the "flash of white" that comes when navigating from page to page in an MVC app? I thought about hijacking all links and pulling the resulting data in via ajax and stuffing them in place, but that sounded like overkill and probably screws up something I haven't thought of...